There are quite a few full time ATCOs who are part time Pilots (ATPLs/CPLs/PPLs) but I don't know any full time Pilots who are part time ATCOs and I think that just about sums it up.
Most ATCOs who fly commercially on a part time basis, got their ATPLs etc after they'd qualified as ATCOs because they had the time, stability of days off and leave and an income to support the expense of training.
Equally, for the most part, our regulated hours and roster system allow us to be available to fly when we want to make ourselves available.
It's a difficult choice to make, because ultimately the basic requirements to be able to do either job are about the same.
I know that flying can pay a lot more than being an ATCO, but it's my personal opinion that, although we do encounter stress, being an ATCO is a far more stable and less stressfull career path when you take into account the unpredictibility of a pilots working day.