Dungeons are a big RNG crap fest? Excuse me for a second.... WELCOME TO THE WORLD OF WARCRAFT! Was that loud enough for you? Just because you can't buy all the gear you need from vendors, that doesn't mean it's a worse system. Buying all the gear you need, is a bad system.
And they are really sodding rewarding, you think 463 gear isn't good enough? What the hell, what kind of gear are you expecting? 500 epics, for what exactly? Oh yeah, farming heroics. That's so sodding hard... And of course random people are going to struggle with LFR at start, they don't even know that fire burns! Wait 4 weeks and you can afk in there again.