It's not so much that it is more aligned with profitability per se, but the fact that each modification you put in the part of the device controlling the radio also needs said approval before being used to transmit - and FCC has been tightening the enforcement of that. It has been on HN before [0]...

Usual caveats about Part 15 vs Part 97 use apply.

[0] https://news.ycombinator.com/item?id=11267443