I mean...yah, if it is a nice city with a great downtown atmosphere. Also helps, as you mentioned, if there is sweet public transit. You can go to a game in St. Louis zoom from the airport to the stadium, and never need a car....could probably fly from Wisconsin to St Louis, watch a game, and fly back all in the same day. Milwaukee isn't what those other cities are nor are the handful of cool things in Milwaukee anywhere near each other. If you could go plop an outdoor stadium on the lake and surround it with the good parts of Milwaukee....that would be pretty cool on paper (not that an outdoor stadium would sell many tickets). But like Fiserv? There isn't that much around it for being downtown and you would have to drive. Then hoping your window isn't smashed out or at least that your car is still there.
I think the Brewers made the best decision in the city they are in and the crowd they have to attract.