Other explanations might include buying SUVs to tow new recreational toys such as a boats, snow mobiles, etc. There aren't many hybrids on the market that are set up for towing.
This is actually a really good point about new "normal" cars these days. I drive a 2001 Toyota Solara (2-door Camry, basically), which has a 2000lb tow rating. It works great to pull my single PWC trailer (~1250lb wet), or other smallish utility trailers around (and, BTW, gives me way more hauling capacity than an SUV or pickup on the few occasions that I need it, not to mention that FWD is better than RWD on slippery boat ramps). Most of its contemporaries also had 1000-2000lb ratings.
Most new cars these days don't seem to have any tow rating any more (which I would guess translates to warranty denials if you have a hitch installed), leaving your only option to buy some kind of truck or SUV.