I think tiering base classes is incredibly deceptive. In many cases, it's the subclass that makes or breaks a classes power. And they also frequently alter the paradigm in which you'd be playing them. Also, as [MENTION=6802951]Cap'n Kobold[/MENTION] pointed out, this seems heavily weighted towards the combat pillar if you're placing Fighter in S tier, despite versatility being one of your criteria.
And as others have said, Wizard does not belong in bottom tier. The reason I feel particularly strongly about this is that, in all the campaigns I've been in (and all the ones I've heard stories of), nobody has played a Wizard except for me, and it's the only class I've currently played twice.
So, A. I can attest to Wizards being awesome. Their low health and the fact that their spells require positioning doesn't make them weak, it just means you need to be more thoughtful about your play (which works to the theme of the class, similar to how playing a Barbarian just lets you be so much more reckless).
And B. Stop discouraging people from playing Wizards! I personally rate (depending on the subclass) Bards, Clerics, and Druids higher (i.e. S tier), but that's because they have more out of combat versatility and healng. But Wizards are THE AoE combat class, because they have Fireball (plus a dozen other similar, just slightly different spells) and every freaking "wall" in the game.
I would put them at least on the same tier as a Fighter, and the two complement each other very well in combat.