I just checked my KS profile, I've backed 181 projects. 110 of those are from the category of "gaming", of which I'd estimate ~85% of those are for physical gaming products (rather than video gaming or solely PDF versions of RPGs). Further disclosure, about 50% of those, I've backed at very high levels (for example, I've sunk > $10k into Dwarven Forge KS1-4 alone), however the other 50% I've probably only backed a single $1. On a similar note, I follow 10 Patreons, but only back one of them (EN5ider!)
As of now, there has only been one KS that fell through and didn't produce what they had advertised. That project did refund people, but they didn't have to according to the KS TOS. There has been one other project that has yet to produce, but last I checked, they're still working on it, it seems they may have gotten in over their heads but should produce in the end.
I just wanted to share random thoughts, in no particular order:
I actually agree with the OP. In that it does get a little annoying to see "Back my KS for this latest greatest widget!" all the time. I really do see your point. However, as with anything in this world, It just "is what it is" and these are the modern times. Maybe think of it no differently than all those goofy advertisements in the old Dragon magazines? In both circumstances, you do get bogged down with trying to decide what is actually worth you spending your money on.
The fact that crowd funding has led to a Renaissance in RPG cannot be understated enough. If you think about this intersection of people growing to an age to be interested in "OSR" along with the ubiquitous access to internet/social media/VTTs/Print on Demand, and along with the crowd-funding aspect to pay for small studios (or individuals) == this is why we have what we have right now, and I think it's overall a good thing.
I do wonder if crowd funding will lead to a similar collapse as was seen with the OGL glut of D20.. but of course it's all different without the physical products taking up space on shelves at your FLGS, etc. Will be interesting to see how it works out 10 years from now.
I back a lot of KS for only $1. I don't really know why I do that. I think I just like seeing people put an effort into making a cool idea a reality. And since it's not something I do, (occupationally, I'm a worker, not a creative type) then I hope that my little tip makes it a smidge easier for those creative people, even if I don't want to back fully at that time.
I ABSOLUTELY LOVE seeing my name in credits. I pay a premium every single time I get a chance just to see that. I'm a total sucker for it. Probably goes back to the point I just made above.
There have been a few KS that I didn't realize would be cool, so didn't back (I'm looking at you Kobold Press), but later on discovered that they do really great stuff. Even though I didn't back a first or second project, I've since learned about them and am now a big fan. So, even if you don't put money into these things, sometimes it's a good source of learning about new RPG stuff.
Lastly, I'll get some hate for this, but probably the one thing I like most about KS RPGs is that I don't see as much of an emphasis on catering to political correctness. If you want an old school type of product with all the childish testosterone driven humor and art from the "good old days", then you can do that so long as you get enough backers to support you. In the end, crowd funding offers more choice, and again, I think that's a good thing.