I believe once the full EAP is ready and then full self driving available, Tesla will enable TACC for all cars.
It's not a "want a free thing" it's a need to be competitive in the market while still encouraging high EAP and FSD take rates. Also, soon advanced summon will be part of EAP, further separating it from TACC alone.
I think TACC is safety related and so do other automakers. And Elon believes safety related features should be standard and available to all buyers. They just can't make it standard until those other features roll out or the take rate will be too low for EAP and the company will not maintain profitability. And the folks who paid 5K for EAP would be pissed today if TACC were standard, but not so much once their car can drive by itself on the freeway and advance summon gives them the ability to call the car to pick them up in the rain outside of Publix.