Not just this, but the other mystifying bit is that titles had to be repurchased for different types of devices. Not only did you have to physically migrate your games between consoles, but like, virtual console titles might be available for both 3DS and Wii platforms, but you'd have to buy them separately on each. And the Switch doesn't have "virtual console" persay yet, but will sell some legacy titles, like the new Donkey Kong release under the "arcade archives" label.

In most other companies, like Steam, Xbox, PlayStation, etc., if you buy a title, you can play it on any platform that supports it. The fact that Nintendo players can't accumulate a library of legacy Nintendo titles and play them on any Nintendo console they port it to demonstrates Nintendo has a strong interest in repackaging and reselling the same games over and over again.