I'm only 40 something, but the Citgo sign has been embedded in my brain since my first Sox game when I was 4.
That said, that piece of ... needs to go. Venezuela, yes. Contribution to this horrible building, yes. Continued interference with modernizing an entire area, yes. Who pays to light this thing?
Constructive solution:. Move it (or just make a new one) as part of Lansdowne redev proposed by the Red Sox. Only turn it on only when the Sox or other major event is happening at Fenway. It would function as a beacon similar to the old Hancock (red is rainy, blinking red stormy, unless it's sunny in which case the Sox are playing). All the drunks can have the beacon they need, and the sign will be transformed into a pop-art piece designating an entertainment zone.
Otherwise, "Whoop (there it is)"