I use Pegasus for everyday work.
I would quite likely be using Thunderbird now, but for all the old emails and addresses I have - cannot readily export/import these- and almost certainly I would have been using it if it had been around when I started with Pegasus.
I really don't see that you can complain about non-support of a future which seems to be pure Msoft, and they disable by default anyway - especially as there are other ways of getting the info across.
Derek