It's not just knives, everything is getting more expensive, and people are spending more $ on things, or at least people are more willing to spend a much higher % of their income on an item. 20 years ago you never saw a swarovski/leica/etc. spotting scope, etc. at the range, now it's fairly common, even though they are $3000+ items. People don't even blink at spending $40-$50K on a car/truck these days.
I think it goes both ways, there are some really great knives available now days with high end blade steel for prices you'd have never seen 15 years ago. A good example is the Lightweight manix 2 in s110v, I'm personally not a fan of the handle material but getting S110v in a knife you can find under $100 is pretty impressive. I think overall the production knife quality has increased, and there's some really great knives out there for under $200.
That said the last few years the trend of "mid-tech" knives where everyone and their brother is bringing out $400-$1000+ production folding knives by farming all the work out isn't impressive to me. Especially when most of them don't seem to be using high end steel, and their fit/finish is not that much better than production knives from the big names, just 2-3x the cost. For those makers that really are doing a lot of the work themselves on mid-tech's this doesn't apply to them. The current trend is everyone is jumping into that arena and most of the examples I see are not that impressive. Knives have become more of a fashion statement like watches now, anything limited or tied to a custom makers name brings big $ regardless of it's quality and blade steel. It's about profits for companies/makers (and there's nothing wrong with that!), that's why S35VN is so popular now, and it's why the liner/frame lock continues to be the standard. Don't get me wrong it's a very good blend of edge holding and toughness but it's real allure for makers is it's available and easy to grind, heat treat, etc.
At the end of the day though it's the consumer that creates these issues. If no one was willing to pay the prices these companies were asking for their products, the market would have to change. As long as people are lining up to buy them, it not only means that it will continue but with the crazy reactions we see to buy sprint/limited edition production knives and "mid-techs" the prices are only going to go higher.