MarkB
Legend
I don't understand how this is a critical hit problem, since a 20 always being a critical hit was the same in 4e.
4e softened critical hits from monsters compared to PCs (PCs get to add extra damage based on their magic weapon, monsters did not), made them less swingy by using a simple maximising of base damage, and more importantly, gave PCs a greater cushion of hit points compared to the damage dealt by any single attack.
I played a 4e campaign all the way through from 1st level to the top of Epic, and can think of fewer than a dozen occasions that a PC was even in serious danger of dying, with the actual number of PC deaths being two.