The reason has been stated already in a variety of ways, the Vikings didn’t think the western islands valuable. They abandoned the settlements and didn’t return, they didn’t find gold, they didn’t find a vast continent rife for exploitation. If they had found their discovery valuable they would have returned and maintained settlements and eventually that knowledge would have spread.
Most fundamentally, the discovery of North America wasn’t “news.” It would have pretty much been a “so what” in Europe at the time. The significance of the discovery is only apparent in retrospect, now that we know that they had discovered a new continent.
One suggestion too was gunpowder. The Vikings found an island where the locals were hostile (no doubt for good reason). The Vikings’ technical level - for weapons - was not that much different than the natives’ - bows and arrows at longer distances, swords (a distinct advantage) at closer range. However, the locals knew how to fade into the bush and appear again at any time. The Vikings were not too bush-savvy. So, it was not a safe place to try to settle, unlike uninhabited Iceland and barely occupied Greenland. So, they gave up and forgot about it.
When the Spaniards and others arrived 300 years later, they had flash-bang killing sticks which were far more effective for controlling attacks from hostiles. they also had much bigger ships that they could live aboard as a secure base for operations wherever they landed.
Yes, an even more concise description. Traveling about Europe the Vikings were unlikely to hold captive audiences with the tales of the miserable barely inhabitable islands in the west.
I don’t know how much the rest of Europe knew about Scandanavia, Greenland, and Iceland either, many of them probably already wondering why the Vikings inhabited the cold northern territory, perhaps surmising that’s what made them such hostile people, so an announcement of a new cold inhospitable island even further away would be like an offer to get an early buy-in deal on new time shares in a location with even more heat, rain, and mosquitoes than available before.
Florida? 
Well, when this happens to you when you land, you don’t think of it as a place you want to go back to. 
Viking kids-Because sometimes it takes a child to raze a village.
Yes and no. Given that the world is spherical, there might have been some value in the idea that you could “island hop” from Northern Europe to China (and the far East) by traveling north west instead of the more standard route of around the tip of Africa. Someone like Columbus, with his erroneous estimate of the circumference of the earth, might have been even more interested. That is not to say that I think Columbus had knowledge of the Vikings travels, but in the 1300s and the 1400s, such tales might have sparked some interest, even if they wouldn’t have in the 1100s.
I wonder if most Europeans who encountered the Vikings even knew how crap their home territories were, given that they always showed up in greener pastures like Eastern Europe, the Balkans, and the Byzantine Empire, and even the British Isles.
ETA, naita made essentially the same point in #7.****
Well the Viking homelands weren’t that crap. Building and outfitting that many ships for trading and raiding required a decent surplus of resources and labor.
Kind of. The Baltic had trees and people, not too much else. It wasn’t northern Italy, or Anatolia. Which would you choose?
Norway! Duh!
The Norse were running out of hardwood trees and weren’t finding much iron ore either. Their raiding and trading was driven by a lack of a resources. They weren’t finding those resources in western islands.
Um, trees and iron appears to be precisely what the Norse kept going back to America for centuries.
We don’t have any evidence that the Norse went to the Americas “for centuries”. In fact, if they had been doing that, and bringing back natural resources like iron, then word probably would have gotten out.
Nothing we have found yet supports centuries but we’re slowly finding more signs of Scandinavians in North America and signs of some iron working. What has been found so far points to bog iron being smelted. No surprise, that remained a major source of iron in America into the 1800s. We have to wait on additional research and findings.
Some related links:
https://www.nationalgeographic.com/archaeology-and-history/magazine/2016/11-12/space-archaeology-viking-settlement-excavation-canada/
What I have read is that the Vikings were looking for Walrus Ivory because of the dearth of elephant ivory due to the Muslim conquests in North Africa and the Middle East. When elephant ivory reappeared in the mid thirteenth century most of the Viking settlements in Greenland and Vinland were abandoned.
I read that article too. Seems eminently reasonable.
When they look at the mediterranean states and their collapse around 1177 BC, one of the things they found was that about 90% of the “Ivory” items they found turned out to be Hippo teeth and bones. In that video, he comments that someone said “But there aren’t any hippos in the mediterranean”, the response to which, of course, turns out to be “There aren’t NOW…”.
Scary too them pointing out how easily the colony in Greenland could have been tipped over the edge with just one storm during the seal hunting season, by pointing out that in 1881, some 80% of the male population of the Shetland Islands were wiped out by an unexpected storm while they were out to sea, and the islands just never recovered.
What was the population like in Scandinavia during this time frame. Was there excess population and competition for resources back home, such that people were both encouraged and motivated to seek a potentially better life on the islands in the west? If so, then perhaps for many it was a one-way trip, and as stated already, it would not have been newsworthy in central Europe that a bunch of poor Norwegians started to settle on some far-flung islands.
It probably won’t be surprising if we find more Viking sites, but that site is not confirmed, as is noted in your cites (no pun intended). And just to be clear, those links talk about the same possible Viking site. I’m not saying you claimed there were two, but if someone doesn’t click on the links they won’t know that they discuss the same find.