If it was such an unpleasant experience, why are so many people there? Maybe the chairs are comfortable. Maybe there is a pleasant breeze, maybe the people standing are just passing by, and anyone who wanted to sit is doing so. If you don't think an outdoor café can be a comfortable experience, you've obviously never been to one. I have my morning coffee at a place like this all the time and it's lovely.
Dude, this kind of thing is everywhere in Europe. It's rare in the US, but it still exists in some places. People love being outside. Just because you're always indoors doesn't mean everyone likes that. I go to breweries often, and as long as it's not incredibly hot or cold outdoor seating is the first thing taken.
The US has been constructed so this kind of thing doesn't exist in most places, but where it does it'll always be occupied.
Those seats look pretty nice, but if it were hot they would just be indoors. There's several people in jackets and suit jackets, so I doubt it's hot. It's all shaded and probably a mild day. Personally, I love going to breweries, and I almost always choose to go places with outdoor seating and sit outside. It's much nicer than sitting in a sealed box all the time to get outside and enjoy the environment when you can.