Monster crits OHK'ing level 1 PC's isn't the problem. The linear HP progression is. Level 1 HP has always been a problem in D&D. You notice it immediately with the safety net levels 2 and 3 bring when you can suddenly take twice the beating and survive nasty crits.
They need to bump the HP of level 1 PC's. Give everyone their CON score + avg HD of HP at level 1. Fighter with 14 Con = 20 hp. Wizard with 14 Con = 18 HP.
Damages could be buffed as well with level progression to maintain balance.
Monster crits are absolutely necessary to make combat feel dangerous and keep players on the edge of their seats.
