Wow. I am really glad I haven't seen angry guests arguing with CM's. That would kinda take the fun out of the evening for me. I'd especially feel sad for disappointed kids. I just can't take joy in someone else's misery or misfortune... The Germans have a term for that -- Schadenfreude
I plan because I like to plan trips. As soon as I can retire from my current job, I'd like to be a
travel agent (specializing in Disney, of course!) Not everyone likes to plan, and they might rather be spontaneous, but then they should expect the popular restaurants to be busy/full. But they could always call guest services and ask, "OK, what IS available for dinner tonight?" And they should be prepared to be flexible on their dinner time, or be willing to have their main meal at lunch time. They might discover some hidden gem -- but even if they don't, they won't go to bed hungry
OTOH...without sites like this, I don't think the general public would understand that they need to think about reservations 6 months in advance, especially for the most popular restaurants.

Maybe 30 or 60 days, but 180 is a bit extreme. At DL for President's Day week, I made ADR's -- but only about 30 days in advance. But that's they way it is at WDW, so if you can't beat 'em, join 'em...
I called for ADR's at about 175 days, and got everything I wanted. Not the EXACT times I wanted, but not bad -- had to take lunch at TH and LC, but we're ok with that, and we'll just do CS for dinner those nights...no biggie...