Regarding your second point, I think it would be a very bad idea. Many apps bring in little money. Mine doesn't even pay for my Internet bill, let alone my other expenses, as a concrete example. If I'm forced legally to maintain them, I won't be able to take the risk of building more. I'll have to quit and take up a 9-to-5 job again.
How much did you pay for that app? A few dollars? For that money, it's not realistic, given the economics, to expect support for a defined period of time. Enterprise contracts, as an example, do have a defined support period but are much costlier. Or you can outsource the development, or buy the app from the developer, all of which are much costlier than a few dollars. Or write it yourself, which is again much costlier in your time. It's simply not financially viable to guarantee that for a few dollars.
Instead, it's more like a one-time thing: you buy what is offered today. There's no promise of updates. Heck, there isn't even a promise that the developer will keep the servers running. If the business isn't working out, despite the developer trying everything possible to make it work, the only option is to shut it down, which is no different from other businesses. This is the unfortunate reality.
How much did you pay for that app? A few dollars? For that money, it's not realistic, given the economics, to expect support for a defined period of time. Enterprise contracts, as an example, do have a defined support period but are much costlier. Or you can outsource the development, or buy the app from the developer, all of which are much costlier than a few dollars. Or write it yourself, which is again much costlier in your time. It's simply not financially viable to guarantee that for a few dollars.
Instead, it's more like a one-time thing: you buy what is offered today. There's no promise of updates. Heck, there isn't even a promise that the developer will keep the servers running. If the business isn't working out, despite the developer trying everything possible to make it work, the only option is to shut it down, which is no different from other businesses. This is the unfortunate reality.