Hehehe, that's an interesting spin. Think of it this way:
If you and I run into each other, probably neither of us will really get hurt. It doesn't matter if you're a weight lifting guy and I'm a scrawny momma's boy, because we're still within a certain range of mass, and given an equivalent velocity, then our momentum is close enough, that our body structure will be strong enough to protect us.
Now say that you weigh 3 times as much as me, so you're like 450 lb and I'm 150 lb. Hell, you just sitting on me is gonna hurt

So yes, it is safer to be you than me, so that kind of is an endorsement for your weight. But, if you weren't so overweight, then you wouldn't be a risk to me, other around you, the furniture you sit on, and your own heart. Hmm.. maybe I'm getting a little off-topic here.
Ok this is fun, so I'm going to use another analogy:
It's probably safer for you to run around with a spear pointed out, since that will keep you from stubbing your toe against other people, but now you're a homocidally dangerous threat to those around you.
So, back to the car vs. SUV thing then. Assuming we all screw up and get into accidents at a comparable rate, then if you SUV people are killing more people, then you are a threat to our safety, and so we're obviously going to try to stop you murdering bastards - umm, I mean, inconsiderate people.
And now for the serious reasons that haven't been mentionned yet:
1) While SUV owners have lower injury rates, they have higher death rates, do to roll-overs. So, you're safer in a minor accident, but less safe in a major accident. So when your SUV rolls over and squishes in your wife's skull, and you're holding her limp corpse in your arms, crying to the heavens, don't expect much simpathy from all the people whose kids were smashed to little peices from some other SUV.
2) The bumpers on SUVs are higher than on cars, for no real reason, other than aesthetics. This causes the SUV to go over top of the car, where it has very little protection, like the glass, decapitating the car-ists (and of course leading to our favorite roll-over for you). So, if that was rectified, then maybe SUVs would be safer for everyone, and we could all sing and dance in harmony. But they're not, so we hate you.
Hopefully that dispelled your illusions about SUVs and that all against them are PC