Were those from the Amazon Vine program? People in the Vine program have 30 days to review a product. They can’t order new stuff if they miss the deadline. There’s a name for those useless reviews – “placeholders”.
I go with 2 to 4 star reviews. It is important for me to see what doesn’t work for a product for a customer. I might have the same kind of fussiness. I look for how the person is using the product and if I’m going to be using it the same way.
While I occasionally have seen cases (especially in regards to restaurants*) where I’d swear the owner’s family must have submitted fake glowing reviews under multiple different pseudo-identities, I think this business of phony reviews is exaggerated by business owners who just don’t like being panned.
As for Amazon reviews of electronics, there are always going to be people who claim horrendous experiences with products that broke down within a couple weeks or never worked right. If you’re scared off by a few of those, you’ll never buy anything. Compare reviews with those on CNET and other sites, avoid the items that are criticized heavily across multiple forums, and hope for the best (plus make sure there’s a good return policy).
*I’ve had pretty good luck with Mexican restaurants which have been loftily dismissed by people as not being “authentic”. 
I ignore the star ratings on reviews except as a general indicator of whether a reviewer’s comments will be good or bad.
Instead, I look for reviews that address issues I have. If something looks flimsy to me and most reviewers say it stood up to heavy abuse, then I have my answer regardless of the star ratings.
I also exclude reviewers who don’t know what they’re talking about. As an example, I was looking for more info on koi pond equipment last summer and I saw a filter that had three negative reviews. However, all three reviewers were using this filter in a way that the manufacturer said not too (too big a pond, too many fish, too much pressure from the pump). So… having eliminated the idiots who can’t read the directions, I went ahead and bought that filter style in the next size up just to be safe.
No, on appliance sites. I have bought most of my appliances in the last decade from AJMadison.com and ApplianceConnection.com. I’ve seen such “my appliance will be great!” reviews many times on those sites. Not so many on Amazon.