not that I'm disagreeing with your larger point but I see this talking point brought up a lot and it's slightly misinformed
yes, VC games are likely using the same ROM across hardware. it's the emulator that's always different. they're not just dragging and dropping ROMs and calling it a day, they develop platform specific emulators to play those ROMs on. you can see this in the Wii U version of NES games compared with the NES Classic version of those games. I'd bet they're the same ROM but obviously the emulation on one is much better than the other.
so again not disagreeing just clearing up a bit of misinformation that I see frequently on here
Let's be honest, though, building a halfway-decent NES emulator has been a student-level project for years now. And Nintendo's built emulators, especially for platforms like NES, for GameCube, GBA, Wii, 3DS, Wii U, and even their own 30-games-in-1 device, the NES Classic. While they can't necessarily reuse the physical code, they don't lose all that research and work when they go to build the next one. They've done the legal legwork. They've done the technical homework. They've poured over the ROMs for anything they want to patch out for legal or technical reasons. If they don't have that all sorted and ready to go for the next time they want to release previously released VC titles, that's on Nintendo to get sorted.
Let's put it another way: how many times do we have to subsidize them learning how to emulate Ice Climber, before they know how to release Ice Climber? Here's a hint: there's been at least 7 emulated releases commercially sold before the Switch even opens up its eShop.
If it's a new platform (Virtual Boy on 3DS Nintendo, what happened?), or one they've struggled with in the past (like N64, and even then), okay. But NES, SNES, GB, that's ludicrous at this point. The work has been done, and if they expect us to believe they throw out that work every time, or that adding extra features already common in amateur emulators is comparable, that's not a valid justification. Other game devs work extremely hard to build new, fresh games with a lot of depth for comparable prices, and Nintendo is milking a bunch of old ROM files developed by employees 20-30 years ago. We don't need to give them too much credit, at least in that regard. Building a good, accurate emulator is hard, but they've already done that. There's no sense in acting like they start from scratch every time, because if they do, they need to seriously rethink their process. And I say that as a lover of old Nintendo games.