When i played this it seemed quite open, but not necasserily criminally open like some maps tend to be.
The problem was cover was sparce and there were not a lot of corners. Players, snipers especially, had the benefit of seeing players come out of cover, follow the medic healing beam and take out the medic when he followed, their was no oppotunity to support team members.
Snipers were not exactly over powered on this map but sight ranges were long and so most classes were underpowered; engineer, pyro's.
I would suggest these for a start:
So far this is your gameplay and it is boring and "clunky" to a lack of better words.
Add in this to allow an option to advance out of the open, and allow players to criss cross the map. Also the blue is supposed to be a legde, this may allow your map to appear less "box map-
esque", perhaps join it with the central platform.. or as access to the the next suggestion.
Also, get rid of those central pillars.. and create a legde or higher access point to which players can shoot down onto the control point. That's supposed to be construction scaffolding..
Hopefully this will allow players to do something other than run directly at each other.
More cover or corners are probably a good idea, the only reason why the point was ever captured was because on the odd occasion both teams were still alive it would only be one player on 3hp or something hiding hopelessly..