I don't agree with this. I miss the days of the monster that was threatening enough to drop a pc in one round if their luck is hot.
However, 4e made it a design goal to reduce a PCs ability to die through sheer bad luck.
Now DMs are always welcome to adjust their game to fit their own tastes. People who want more lethal games can bump the monster damage, add more damage on crits, etc.
But the baseline should hold to the design goals, and there are a few monsters out there that break that guideline.