The thing which makes people "angry" about the 30FPS lock is that we're not in 2004 anymore. It's 2014 and people expected consoles would finally catch up to PCs. I also believe the majority of people QQing about the FPS locks are the ones who said PCs suck and aren't worth the time or money. Because playing at 60FPS on 4K HD is too mainstream.
Conversely, if it looks amazing but the fps is "low", does it matter?
Depends on the amount of low we're talking about here. Anything under 20 FPS? Barely playable and not worth the time or effort. 30 FPS? It's ok with me since I've spent 3 years playing games on lowest of the low so I know the feeling of playing at 10 FPS. However if it's locked at 30FPS and suddenly a game has to load something large or a large amount of, lets say, NPCs the FPS will drop for a few seconds and it will be quite more noticeable than if it dropped from 60FPS to 45FPS.