It seems like the various kitchen uses of high-temperature silicone (baking sheets, baking pans, oven gloves) have only recently come to the market, in the last couple of years. Why is this? Is it a new invention or did no one think of it or too expensive or what?
I don’t know what you’re talking about. I’ve had such items for, well, longer than I care to reveal.
Really?? I’m really surprised. I’ve been seeing article like this one around recently, calling it “the next great thing”.
They do mention that the Silpat baking mat has been around since 1982 in France, but I’d never seen one before last 2003 or so. None of my cookbooks mention it in the cookie section, and I’d think they would if they knew about it.
The baking sheets have been out a good 10 years. Ditto the spatulas. The oven gloves are fairly new to the retail world, from what I can tell.
It takes awhile for items to filter their way into the average American kitchen–unless it’s a George Foreman appliance.
Silicone basting brushes are great.
Why? Does it make the food taste like it’s burning? 
When did the FDA approve it for use in cooking? Maybe thats the reason? Perhaps the approval is fairly recent.
It’s just a trend. Some people swear by them, but plenty of others have dropped a lot of money on them and hate them. It only takes one company to start making a little bit of money on them to convince everyone else to start pushing them, and it’ll die off just as fast.
It’s not a new invention. Silicone potholders have been used in laboratories for 20 years at least, though they weren’t called potholders (“Hot Hand” was a brand name, they were generically called “glassware handling devices” or some such lab-appropriate technical name).
As for why they recently became popular, search me. Silpat sheets may owe something to Martha Stewart, who raves about them, but I don’t think she uses any other silicone gear.
I’ve had a Silpat mat for 4-5 years now, but when I got it, it was hard to find and very expensive.
Now I have lots of silicone cooking utensils, all purchased within the last year or so.
I think that while the mats themselves have been around for a while, the other things (spatulas, oven mitts, etc.) have been “in the works,” at least for mainstream retail. You certainly couldn’t use a Silpat mat as a spatula or baster without giving the material more “oomph.” The Orca silicone hot mitts are interested, but too thick and clumsy to be good for much of anything. The newer, thinner mats that double as trivets and potholders are more useful, even if they can’t protect your hand from boiling water if you reach in to pull out a hard-boiled egg. A few months ago, I saw a silicone oven liner that just lives in the oven to protect the bottom from spills, etc., but which is not much thicker than a piece of paper.