I'll be honest I never understood the boards whining about tanks dying too fast.
Seriously the only time I'd ever seen this situation happen is late game team fights where they get focused on by like 3-5 people and killed after everyone has their pen items and such. But early-mid game all I ever saw was these guys taking very little damage and using their decent base damages to take down squishies. ADCS in particular not being able to afford the sustain or the armor pen items they need that early. But the moment they started to purchase these items their roles reversed. Really it all just felt like tank players lying through their teeth and basing all their arguments off of late game team fights.