Of course. And that's why not every game is being ported to Switch. But as we are seeing, there are a lot more ports being announced now than prior to Switch launch and it's precisely because it has been proven economically viable to do it.
There are also few situations when a publisher must decide between PS4 or Switch for a port given that PS4 already gets most games to start with....meaning those resources (porting studios) aren't really having to fight between consoles.
If I were a dev deciding between a Switch or Pro port, I would probably choose Switch most of the times as that would likely have more chances of added profits. I would say just some specific genres/titles would be bad investment to choose Switch over Pro.
And yep you are right, some ports aren't done because of the ROI not being there. Sure sometimes devs/pubs make a bad call, as it seems like that title would do good numbers on Switch with the port not being hard or taking to much of the original, but I think that is the smaller portion of cases. And you are also right that Switch is getting a healthy quantity of ports on what is feasible on the system without major redoing of the game and also shall make some other titles start with Switch already in mind (which may impact the PS4/X1/Pro/X versions unfortunately) and make the Switch version very competent.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"