To each their own, if someone has interest in art, culture and history I would definitely choose Venice above Munich. I know many people despise Venice because of crowds, over tourism, tourist traps and so on, but it is undoubtably a unique/exceptional place in the world full of history at every corner and even in its decadency fascinates me every time I visit. Just go outside 100 meters of the usual ring Piazzale Roma, Station, Rialto, San Marco an the crowd disappears, you can still find decent drink/food and relax, sure July August can be very hot. Munich is a nice city, but not too different/special from other mittle European cities in my view.