In a way they do already charge as they're only available as part of the Online package (and N64 + Mega Drive are only on the deluxe Online package, whatever that's officially named).
As for why aren't those games sold individually, Nintendo used to do this with the Virtual Console on the Wii U -- which was literally their previous console. I'd wager there wasn't enough money in it to do that again. Or that they feel the Online subscription earns them more money than selling those ROMs individually.
Let's also not forget they've relatively recently launched a range of mini versions of their classic consoles. Granted they're just (IIRC) running emulation on-top of Linux but it still demonstrates that they're aware of this market.
Much as we'd like to assume Nintendo are incompetent because they're not catering to our specific needs, I think the more logical explanation is that us retro gaming nerds are a vocal minority. We love to moan about how much money Nintendo could make but if that were true Nintendo would already be doing it because they had done it previously, recently in fact, and thus already have figures about how popular these features are. And given how successful they are as a business, and how successful they are at milking their IP, they certainly wouldn't pass up the opportunity to sell ROMs if they felt there was a market there. But when you have Switch games selling for £50+, even years after their release, it's hard to disagree with Nintendo's outlook that Switch titles are a bigger source of revenue than re-releasing the same ROMs they've already re-released several times over.
As for why aren't those games sold individually, Nintendo used to do this with the Virtual Console on the Wii U -- which was literally their previous console. I'd wager there wasn't enough money in it to do that again. Or that they feel the Online subscription earns them more money than selling those ROMs individually.
Let's also not forget they've relatively recently launched a range of mini versions of their classic consoles. Granted they're just (IIRC) running emulation on-top of Linux but it still demonstrates that they're aware of this market.
Much as we'd like to assume Nintendo are incompetent because they're not catering to our specific needs, I think the more logical explanation is that us retro gaming nerds are a vocal minority. We love to moan about how much money Nintendo could make but if that were true Nintendo would already be doing it because they had done it previously, recently in fact, and thus already have figures about how popular these features are. And given how successful they are as a business, and how successful they are at milking their IP, they certainly wouldn't pass up the opportunity to sell ROMs if they felt there was a market there. But when you have Switch games selling for £50+, even years after their release, it's hard to disagree with Nintendo's outlook that Switch titles are a bigger source of revenue than re-releasing the same ROMs they've already re-released several times over.