I don't see a lack of forced induction cars at the track at all. Most of the local street car shootout type stuff is mostly turbo and supercharged cars, mainly newer model stuff. Almost all of the older cars that run those type of races are on nitrous though, but a couple are turbo'd. Now if you're talking just Mopars, then yeah...serious lack of FI cars in the general Mopar world. At big races (like Lights out or no mercy), about the only Mopars you'll find are blown hemis.

Me personally, it's b/c I don't want to hack up my car. If I were to go w/ a turbo or procharger, there'd be a lot of fab work involved and there's very little room under the hood. Nitrous is a lot cheaper initially and I'm old school even though I'm on the younger side of this Mopar hobby. I fell in love w/ the late '90s/early 2000s style of fast street cars and they were just about all nitrous.
Granted I have a lot of money already in my big hemi, so going turbo wouldn't be as bad on the wallet if you had a cheaper motor to begin with.