That's the point of the facemasks, to protect others. That's been known since the beginning. You wear a facemask to protect others from yourself, and in turn others wear facemasks to protect you and others themselves. Then you have a holes who are inconsiderate.
100% true, the face masks are not to protect yourself - you might already have corona and don't even know it - it's only to limit spreading it to other people. Even though masks are no complete protection - they definitely help. So not wearing masks is actually a risk for other people more than yourself and should be fined.