Lots of reasons to move though..
New to an area
Looking to a higher standard
Looking for an easier standard
Maybe they just didn't feel at home
Moving jobs, so as they want to play as close to home as possible rather than live one side of town and play the other (much easier for post match stagger home
Lots of legit reasons
(Speaking as someone who has moved clubs a few times in a small space of time - hell, for one club I used to drive for 2 hours just to play home games, then of we played teams like Peterborough town we'd have another drive on top etc.. So isn't lazyness or lack of dedication etc)
New to area, fair enough.
Higher standard over 25, probably not good enough.
Easier standard, probably drop a level at your own club.
Didn't feel at home, means you have moved recently and it us likely to happen at the next club you go to.
Moving jobs, same as new to area if that is the case.
This is an amateur game for 99% of us on the forum. Be part of your club, make a difference at your club and support it.