2. only every second U2 goes there
3. disregarding the doubled U2 wait times, it takes 40 minutes to get to Karlsplatz, 46 to Stephansplatz, 47 to the main train station, 53 to Westbahnhof, 54 to Landstrasse -those times get much worse if you don‘t live centrally in Seestadt. And those times are AWFUL for Vienna, anything over 30 minutes is awful.
4. The „See“ is actually a joke
5. if you live there, people won‘t want to visit you as it would take them over an hour to get home (unless you take a taxi or have a car)
6. is generally awful without a car -unless you live and work there, this is a big deal as you don‘t usually need a car in Vienna
as for the concrete desert, what are you asking for? isn't the inner city all asphalt and bricks too? there are parks. but seestadt has green spaces as well. according to the map it has even more than the inner city. but it's all new and it will take some time to feel comfortable and lived in. you have to start somewhere. i mean i get you, nobody wants a concrete desert, nor a concrete dessert for that matter. though the latter might make a good projectile to show your appreciation to the cook.
also how is the "see" a joke? it's water. sure it's not the "alte donau" but from the photos it looks no worse than the donauinsel.
my cousin waited for years to get an apartment in vienna, and they finally got one in the south. from the looks of where they ended up i think seestadt would have been a nicer option.
north east of the danube is the only space where vienna can expand. there is some space to the south of vienna too, but not as much. and probably living in the south would not feel any better.
Well connected, long time residents who have access to flats in the inner city always feel superior to the people who move to the city after them, and have to live on the outskirts, that doesn't say much.