all these downvotes because why?
does anyone even realize what All Random means?
It means, you wanna play AP Nasus in URF PvP? too bad, you're stuck with Yasuo
if you somehow do manage do get the champion you want, its not even close to likely that you'll get them any time soon again
and what if I wanna play AP Nasus all day? I can't do it on pvp, and face it, custom games just aren't the same
you own 100 champs? that's 1 / 100 chance you'll get the champion you wanna play, meaning you'll have to play about 100 games to play them for a single match, which may not go how you want it
not to add the teams may be more balanced sometimes, but when people get champs that they aren't used to, or just bad champs on urf, they'll probably lose . . . hard, and that's not fun at all
and does this mean no more bans like on ARAM?
tl;dr
you don't get to be who you want, when you want = not as fun
if you lose to that Zed or Sona, at least you lost playing the champion you wanted to play