The issue of losing a home game isn't really that important when it's 3 out of 162. Also it has to be a game that matters, nobody cares about pre-season. The stadium occupancy rates at typical MLB regular season games (for most teams) means that the fans can still attend games easily any time they want, there are no sell outs every week (for most teams).
The issue for me is that there are no purpose built stadiums for baseball in europe which really affects both the game and the fan experience. Also baseball is a niche sport, whereas NFL is hugely popular. I can't ever see baseball becoming anything more than that in Europe. Baseball is an acquired taste, and let's call a spade a spade, for most people it's an extremely boring, long winded sport.