Wow, its the daily "Nerf Riven" thread, or is it bi-daily now since these are constantly appearing on the board.
First, you need to learn more about a champion before you whine here. Riven has no sustain. She has a shield that has a cooldown and that is it. She's got some of the worst health regen stats in the game.
Second, early on Riven has the same cooldown problem everyone else has. Yes, she'll stack CDR if she gets fed, but if you don't feed her she's living with her cooldowns are high enough to give you opportunities to attack her.
Third, for an AD melee character Riven is squishy. Most Riven's build her glass cannon and rely on her shield, life steal and the fact that people like you refuse to learn to play against her or to build any armor.
Sorry, but I don't main Riven and I know exactly how to defeat her. I even ended up in an Annie v Riven midlane some time ago and beat her during laning phase. (she fed later though.) Beating Riven just requires that you know her moves and are willing to use minions to keep her from going all-in on you without burning her abilities. If she has to use Q to get to you and burns 2 of the 3 to get to you, you have time to fight back.
Also purchase armor. Armor is life against an AD bruiser. If you aren't purchasing armor you deserve to die fighting a Riven.
Sorry, but this complaint is 100% based on you getting "butthurt" because you refuse to admit that you haven't taken the time to raise your own play to a reasonable level. Riven is considered junk in the top tiers of the game because she can be shutdown so many ways. Riot isn't going to nerf a champ who only dominates in the bronze/silver rankings because the players there refuse to learn how to counter a champion.