Re: Someone else's computer
This is much more sensible. Opening up the API is nice and makes it possible to write an alternative server, but certainly doesn't guarantee it will happen particularly for minor products. Even if it does help users of this forum it won't help the 99% of people who don't know how to run their own server. Instead, financial incentives need to be aligned instead to let consumers compare cost of products properly up front.
I'd combine your suggestion with an obligation to say in the product specifications/advertising how long the company will provide the service for (as a minimum). It's not reasonable to expect subscription-free service for ever, but it should be transparent when you buy. If they don't keep the trust fund topped up sufficiently to run it for the remainder of the time, and the product is withdrawn or the company goes bust - director liability for the shortfall.