Are you saying that actions/decisions taken for sentimental reasons are somehow invalid?
Just because you "don't see this attachment" doesn't mean that someone else isn't entitled to feel how they do about something that would bear no significance to you.
I don't mean to attack you personally, it's certainly an interesting topic - but if one takes your view to a purely logical conclusion we'd all be robots, taking calculated and emotionless decisions about everything.
Anyway, even if no-one actually had a sentimental reason for wanting to hold onto the property, there would still be plenty of scope for feuding - families tend not to need much excuse!
If I could offer my tuppenceworth, I would say that maybe some people see that particular place as an anchor, that gives them a sense of place/belonging. If you've moved around a lot in your life you mightn't feel the need for such an anchor, but as someone who has never been away from my birthplace for more than about 10 days, I can understand that mindset although I'm not sure that I'd subscribe to it.