They don't even like Dodge for its RNG. There is no excuse for keeping champion abilities that work in similar fashion to the Konami Code. If it's a legitimate combo, fine. If it's a random string of inputs that spits out a new and unique outcome unlike the 5 abilities you have on your screen, and you're the only champion with that "ability", That should not stay.
And DotA is a bad comparison to make. Sure, code allowed creep denying, but part of the reason LoL exists is because they admitted to themselves that such an ability will hold back an enemy's gameplay in ways difficult to balance, and they held that out of their game. Afterall, AD characters have a general advantage when trying to deny over a support or caster, since a caster can't damage their own creeps with spells, usually. Riot made the right choice in removing that, and even removed random-like effects such as dodge and universal crit chance (for those who remember, every champion used to have inherent crit chance), yet somehow thinks giving Riven a new free Cleanse effect is something worth keeping, with no clarity on the effect whatsoever? No, this isn't the straightforward gameplay Riot has generally been known for. Riot is the company that boasts about their clarity. Yet, for some reason, some of these champions are given unique effects that you not only can't read up on easily for one special champ, but then you need a sandbox to perfect it in the first place, which they still have yet to release. I am glad they did decide to implement it, from the sounds of things, though. Now we'll have to just wait to get that... soon...
Riot's never been perfect, but allowing Riven's shenanigans has been a particularly glaring low in their game over the years. Every once in a while, we hear about champions getting clarity injected into their kit, for both allies and enemies. For whatever reason, Riven is the grand exception of that. The kicker for me is that they even removed invisible autoattacks within Nidalee's kit to help balance her out. I'm in shock that she made the cut, and Riven's still Riven.