You've misunderstood. One is RAM, one is storage.

I don't think they want to drive developers away, I think that the removal of the 17 inch MBP from their line was a sound business decision the only market left for them are intense gamer who are on the go (i.e 17-20 somethings in school) and developers. The MBP has never been seen as a first class game system so they where never really competitive there and developers are a small subset of the computing market and not all of them prefer a large monitor.

Soldered in ram was a decision to reduce the overall size of the MBP to make it thinner. Again this probably appeals to the large consumer market.

I don't know the reasoning for not moving the line up to at least 32GB of ram but I would assume their cost to produce to market segment came to a higher profit calculation by not doing it, maybe it offset the cost of the touch bar but that is speculation but I assume they had their reasons.

I don't think it is an intentional effort to drive developers away, rather calculated attempt to chase the largest market segment.

RAM vs. Flash storage. You're comparing apples and oranges here.

For reference the top end in flash storage for the MBPro is current 2TB. That's 16X the iPhone's max 128GB.