Mosques are analogous to churches, not monasteries. Even as a Muslim, I'm not sure what the Islamic equivalent for a monastery is, since monasticism it is discouraged in Islam.

And this is bad how?

I live in a German population center with many many mosques and it affects me in exactly zero ways. I know _no one_ who regularly visits a mosque, let alone trying to convince others to join.

We have religious freedom in our constitution. Aside from some stupidly minor exceptions, Germans aren't somehow converting to Islam. They are leaving religion in general.