I mean, unless folks want to pay more money so the software can support both old and new stuff, yes, support does have to be dropped.
But the Fact is they will just disconnect their older O/S from the internet and it will still work. So that does nothing to stop them from using their old O/S offline and it will work just fine. If they really wanted to do that then this is the wrong way of doing it. Your just make users go elsewhere to find a paid program that will still have support for their O/S. You don't grow your base users by killing off your core users. Forgot to mention if that was the only game in town but it isn't there are plenty of others that will want those users to buy their software to compete against DVDfab. So this kinda strategy is always bound to fails and they will come back because without those DVDfab users they wouldn't be where they are now. Companies that forget this will find it hard to rebuild their reputation back and trust from the users.
...Okay? So you want software that's bloated because it continually adds features AND supports every operating system, software with bugs (again, because it has to support upwards of 11 major operating system revisions, ignoring all the small updates each one has)....
Keeping an old app & updating it to work with a new OS is fine, until the new OS breaks the old software.
Which means they end up having to build two versions of that same software with quite a few differences.
And the hardware supported on each OS? The ways to access all that hardware change significantly.
Keeping track of all those changes, while making sure you don't break support in the process (and finding workarounds when stuff does break), costs something. Time, money, planning, all of that. It's not realistic to keep supporting something that neither manufacturer supports (Apple hasn't supported 10.6 in a while, and Microsoft hasn't supported XP in...yeah).
Even the tools used to build the software itself drop support for older versions of an OS regularly. That means that on top of building for Mac AND Windows, they have to edit and build the code twice for each platform.
Nah, not worth it.