Or is it just me? I know certain brands are known for cutting jackets narrow in the shoulders with very high armholes (Guess, Miss Sixty, etc), but this seems to be becoming more of an issue regardless of brand.

I can't tell you how many jackets I've tried on over the last two years that fit everywhere but across the top of the shoulders. Going up a size just makes the jacket too big but the shoulders are still too tight. The Gibson linen blazer in the YLF store is one. I'm not an IT and it's not been a problem until recently. What gives?