Weird.
I read about this last year. It’s a place named the 90° café bar lounge.
But, absolute zero worries. Right next door, there’s Brändli (confiserie + tea room). Delicious home made fruit sorbets (sorbetto al mandarino), sparkling wines, and I’ve heard they offer coffee too haha. Brändli also offers chocolate cubes with grappa inside, sadly only by the pack, no individual cubes 
Most importantly, I’ve been to Brändli. People is talking, normal coffee place. No grumpy loners solving crosswords or whatever and demanding silence.
Doesn’t sound very child friendly either 
They are minors and so long as it is a blanket ban it is not decrimination. Still good click bait writing from a wanta be journalist.
Back in 2013 we went on holiday to Malta, in M’Dina there was a restaurant that had a sign outside which said “unruly children will be sold as slaves”. There was police station across the way with a sign outside that said “No time to go to Mass? Get the Malta app!” which made me laugh as well 
Lots of places in N. America which are off-limits to “minors”.
