No, I'm open to possible reasons behind the ports. I'll go with your question. Why has sony done so many ports? To make more money and possibly for other reasons such as filling in holes in the release schedule. Hopefully the practice doesn't pull resources from other new games. You take this shit a little too seriously.
Personally, I'd rather these fuckers (yes, sony is included in that) just produce new IPs and release new additions to the established series. Ports are good for the companies but that doesn't put a new IP in my hands.
But you dont have any other possible reason behind great ports from failed Wii U console that just very limited number of people had, remasters that not just are definitive versions but they offer full handheld mode, that will make Switch lineup more diverse and stronger and that will feel gap, and offcourse on those ports Nintendo will earn load of money.
You need to realise that port is not equal new game, port can be done in few monts with little resources, new games require much more time and much more resources, so it's not like that instead TLoU Remastered we could have TLoU 2 or instead MK8D we could have MK9, Sony said that TLoU Remaster was done in 6 monts, while they will be working few years on TloU2.