[coldtea]

Don't know, haven't seen it as often.

Money and existing customers depending on you and you depending on them provides a good motive to not do (1) and to avoid (2).

Also a lot of no-OSS software, especially of the desktop variety, is unpolished and un-finished, usually a moving target, so (1 -- the owners moving on and nobody picking it up) is more damaging for its user compared to some proprietary software being abandoned which he can still use for ages as is.

For example Microsoft is legendary for avoiding (2) at almost all costs, to the point were 20 year old Windows 98 programs still run as is on a modern OS. Heck, people still use VB6 which was superceded like 13 years ago... If you pick a software with a good following, chances are they will continue to support it.