First, it's a shame the old Omonia square was destroyed, but it's not the first time something classical and beautiful was replaced with a monstrosity. Look around Athens and you'll see ugly apt. bldgs, garbage, and cacophony.
Anyway, so I understand.... If a country says it values freedom and liberties, should it allow people to believe in Zeus even if this goes against majority's worship preference? Instead, do you want to copy backward dictatorships, and oppressive theocracies?
And, if you don't allow for a mosque to be built, what are you preventing exactly? That those Muslims will not find a way to pray?
Instead of promoting enlightenment and fighting superstition with education, some people choose to kill each other on the debate whether the deity likes pork or not, and whether he has designated some sheeple as the chosen ones.