This would be perfectly fine if it were applied as a principle equally across the board. The issue is the double standard, that it totally makes sense for a RTwP to HAVE to include a TB option but a TB game shouldn't waste resources on adding a RTwP option. It is this double standard that I am questioning.
A game designed around TB will have fewer, more meaningful encounters and games designed around RTwP usually have a higher volume of trash encounters. Translating those two between each other... A game where the encounters are designed around having RTwP would be minding numbing with a TB system slapped on. A game where the encounters are designed around having a TB system where a RTwP system is just slapped on will simply have incredibly difficult encounters.
I hope they just pick a system and make it good. It's wasted resources either way if they're not going to dump a massive amount of time in balancing to make them both feel good. A BG1 & BG2 TB conversion would suck just as much as a D:OS 1&2 RTwP conversion, IMHO.