Short answer: Yes. Regardless of how old the system is, the user is a customer and will still be, and any service provider (Electrum), should always tend to their customers no matter what, and it should not be an one-time off deal. You buy, I take the money, and you do whatever you want? It should not be this way.
Like what you mentioned, Microsoft continued to find bugs in Windows 7 and warns its users to quickly update and patch it. Remember WannaCry and Petya ransomware attacks? They exploit bugs on old computers, which is why it is the companies' responsibilities to look out for its customers and help them. I would say Microsoft has done enough, but more could have been done to warn its users.
If you are a user of Electrum with an older OS, and something goes wrong, who should take responsibility? Is it the user that failed to update? But the thing is, when the user downloaded the version (that was considered 'new' at that time), it was said to be safe and 'error-less', so the companies/devs should be the ones to take action if anything goes wrong.
Well if the devs find bugs in the older versions, they can always fix it and perhaps make its newer versions even better by learning on their past mistakes, so not exactly waste time, but I get what you mean.
