The Ford "family" doesn't own the lions, Will Ford does. A bit of a difference.
There is a real valid reason for this and it was explained to me a long long time ago, the losses are used to offset the gains in other investments and if you notice something when Ford stock is down and there is no money coming from it, the Lions seem to be spending a bit more money and do a bit better in the season.
But Detroit isn't a real sports town, it is a fair weather fan town and nothing like Chicago or Boston or even LA.