Yes that is true but we must not forget that Bitx and uBitx are affordable for a beginner amateur radio and that adding a lot of additional features will confuse more than one if the price was a lot most important.
What makes Bitx interesting is the price that allows a beginner to start and a seasoned enthusiast to experiment with many things. We are still in the QRP traffic domain.
Or we must add these features in the form of additional cards that can be purchased or manufactured later.
I think the most desirable goal would be to make a modular package that everyone can change as they see fit.
Lets not forget that in some countries HF equipment is quite expensive and therefore many of the new radio enthusiasts are starting in CB 27Mhz AM/FM. In my opinion this modes are also quite useful. Also on amateur radio level in 10 meter band in the summer when the propagation is open many nice QSOs can be made in FM around 29600Mhz. So in these case why not to have AM/FM