That's up to you. If you think about it this way; if you had the option to make a new game or a port, and its going to take as much time to make a port of a game or make a new one either way, would you still do it?
Now if it were an easy task and almost hands free, sure why not. But why do it if it were a difficult task
Here's an example I can give:
Take the Legend of Zelda Ocarina of time for the 3ds, the game was released in 2011 (N64 was released around 19XX) That's something worth porting to a system, similarly with the recent Crash Bandicoot release for the PS4 (released somewhere in the 90's the latest DOOM Game found on PS4, PC (and now) Nintendo Switch.
Mario Kart 8 was a great port, never played the game, never owned a Wii U. After about maybe like, 30 or so hours? I got bored of it, it was a great game but why re-release something already released from 2012 or so, and besides MK9 would have been good enough to have on the Nintendo Switch; Virtual console could have waited.
Alternatively there's the other argument; the player should have variety in what they want to play (by that I mean porting every game possible, whether its on PC, PS4, WIIU, WII, GC, N64, PS1, PS2, PS3??) And yeah that's also true but I if I already played a game maybe 2-3 years ago, and maybe lets say If Infamous2 came to the Nintendo Switch and Gran Turismo (for whatever reason.) Sure I would be hyped and think that's great, but would I go out and buy said game for 59.99 when I can play it on my PS3 for 9 bucks?
And that's great, I think every game should be on every console or PC possible exclusivity is something that is sometimes really stupid and not everyone can afford all four operating systems to game (Playstation, Nintendo system, Computer, Xbox). I'd be pretty frustrated if what I just bought only had a fraction of games that Steam has or Playstation. But the other question; if it wasn't as easy to just simply say "were porting this game here" would you do it? That's the real question you need to ask. Because I would be overwhelmed if someone told me they wanted (for whatever reason) my Python.py game on Cobalt.