While Seiko has been raising prices, they have also been closing dealers, making their lines more exclusive. I think they see the Swiss luxury brands being successful with fewer dealers and prices that have almost doubled in 10 years. They are playing a bit of the same game. I'm sad that Seiko prices have gone up, but I really don't think their most popular watches under $1K, like Prospex divers and Presage are at all out of line compared to prices of brands like Oris, Tissot, or Hamilton.
Seiko's midline watches at $1500-2000 are a bit confusing to me, there's not enough to set them apart from the under $1K. Some of the midline limited editions are downright ugly IMO.
Is a Grand Seiko worth their current prices? Sure, if you believe that Omega, Rolex are worth their current prices.
The real problem is not Seiko, IMO. I think all watch prices have gone up too far in 10 years. But apparently the market will bear it. There are enough people people willing to spend $5K and $10K on a luxury item, even though the vast majority of those people really don't care that much abut watches in general. The watch is just a part of their luxury lifestyle. And it's something that can go with them and show off everywhere they go.
Before you criticize a man, walk a mile in his shoes. That way you'll be a mile away and you'll have his shoes.