I don't think there's a particularly large overlap between Switch owners and PS3/Vita/PS4 owners, let alone the tiny speck that is PC gaming in Japan.
Why not? Switch is essentially the successor to Vita, I'm sure alot of Vita owners have transitioned to Switch. As for PS4, it and Switch complement each other well, you think the people who like big 3rd party titles and the people who like Nintendo games are completely seperate audiences?
Regardless, there's a big enough overlap that a game being ported for the 4th time isnt going to sell a ton of units.
This isnt a Wii U situation where a game sold less than its potential because of the install base, PS3+Vita+PS4 have sold close to 25 million in Japan so almost anybody who wanted to play a remaster of games from 2001/2003 has done so already.