I think of the same way. There has barely been any activity in my area with regards to underworlds yet LGS sells them. I dont play often, but the models are unique, easy to build being push fit, and i can concentrate more on painting the models.
Underworlds was fun in beginning.
For the OP, in regards of evangelizing TCG players, have you seen/played the warhammer 40000 commander decks? I thought that type of game covers the TCG itch.
I dont know if there is a market for 40k underworld equivalent. I guess i dont feel same way as you do, but if it happens then i am happy for you. :)