Dallas has plenty of density as proven elsewhere. As for wanting it, people don't want what they don't know. How they would act if something existed is very different from what they say.
Proven where? DFW is not as dense as you might think. Last mile is an incredibly hard problem to solve when it comes to transit and you add in unfavorable weather and it’s a not go.
Good luck though! Just sharing as a member of the DFW community has taken dart and bikes a lot. The metro is absolutely not dense.