Tanks are so worthless in this game it's disgusting.
There is literally no reason to pick a Tank/build tank these days.
Hp doesn't matter - BORK Armor doesn't matter - LW/BC/Yomu MR doesn't matter - Void staff/Liandrys
Trying to stick to someone is nearly impossible. Nearly every champion these days has some form of a gap closer/untargetable/invulnerable/shield etc. into their kit making it nearly impossible to stay on something.
Not to mention marksman. You finally somehow manage to get onto one of those pieces of crap and by then you're at half hp and being kited because 500+ combined with a gap closer isn't a bad thing at all..eh?
Sure, you can argue "muh cc" you're better off bursting things in this meta than you are trying to cc them. "B-but I went Amumu and I cc'd a caitlyn and my assassin deleted her"
If your assassin is "deleting" someone they're able to "delete" Them without the cc
TL;DR Tanks need buffs or anti-tank items need nerfs
OK
.... Useless I think not.
or even 
Just snared you
Just slowed you down
Just knocked you back and set an AoE slow out.
Just kicked you back
I can go on for dayz. How exactly do you plan to do anything with nasus when you can't even reach your target and your hp is being chunked away cause lol LW/Bork/IE getrektscrub.
thats just items and summoner spells not counting W and btw You really think a Nasus can't juke. And please pray for that exact team comp to use against 1 champ while the other 4 on my team are dealing TONS OF DAMAGE.