I guess I was being nice to old programs. Also, these are programs that a lot of external tools interact with. Nobody cares about where firefox stores its data- except the now almost dead flash plugin.
Yes, very good point I do think that the older programs/projects have to plan a migration which really can be challenging. I think there are some that might care for example selenium might have the mozilla directory as a default and some might hard code it. The orchestration of such a change is difficult because I don't think too many people read changelog or really keep up with upstream modifications.
