Nerf Riven

Why is it that Riven. A champ which is never built tanky, can take and jump in 1v4 and kill everyone without going below half when they don't have one single item of tank gear? Oh right its cause shes totally broken. Her shield needs to be scaled back unless she builds AP(Much like Shen's shield which they are changing) and they need to make her abilities have a longer CD. Having her abilities up 100% of the time(with the exception of the rather short CD on her ult) is ridiculous. I was playing Illaoi which is an admittedly broken champ herself and a riven of relatively equal stats came and annihilated me. I got me E and Ult on her and she just tore me apart and I had 2 armor(Sunfire and Randuins) items cause I was dealing with a Fiora. No tank items, no armor pen and I got all my abilities on her and she raped me. What in the ever loving fuck. Every Riven I come across is ridiculously OP. People keep saying she takes a ton of skill which I am sure at a higher level it does but even at low ELO she will rape people. Why are they wasting their fucking time changing a champ like Shen when they could be fixing a totally broken one like Riven?