Some 3.5 Homebrew from WotC

[Gnorman]

This means True Necromancer is a good class, which gives us a rubric for power. This means that these rules focus on fun over mastery, and work at the level of power where a druid is a woodland loner who uses his animals for accounting instead of as a power house. This means that the warlock is a viable replacement for a wizard. This means that monk isn't a bad class, just a weird one.

And yeah, from that point of view, where the wizard is in actual danger of being swarmed by goblins and then who will throw all those fireballs? Then, it's worth giving the wizard an extra hit point. The rogue already consistently out damages him, gets through locks without blowing a previous spell slot, and can wear armor! He'll be fine.

While I can't speak for every designer, Monte Cook at least admitted to making system mastery a large portion of the 3.0/3.5 design process, in his essay about Ivory Tower game design. By that same logic, Toughness is a good feat for a wizard - it's a whole three hit points!

As I said: I never trust anything Mearls designs.