Devil’s advocate: the login requires a server, so even old versions won’t work unless they keep them online. And without support, they will be easy target for hackers.
I hate this, and honestly the best would have been to not change the logging at all. I bought a game that didn’t need a MS account to play and this change doesn’t bring any benefit.
Also lots of other places (YouTube as an example) allow you to migrate your account indefinitely, over a decade after they were purchased.
If you self host an older version, you can allow non-authenticated users. I did that for years so my kids could play on our LAN with just the one license. I eventually bought a second license, but we still haven’t played outside our LAN.
Keeping up a server that allows migration has negligable costs for a product the size of minecraft. There is no excuse…
Keep that in mind next time you consider giving money to Microsoft. I definitely do.
I’m just playing devil’s advocate, and never es l was this name more appropriate.