I am sorry but the idea that masters play for a win with the stonewall with the black pieces but cannot also do the same with the white pieces makes no logical sense to me. Ok I understand that they dont like the idea that they cannot get an opening advantage with the white pieces but it still is difficult to comprehend. Is there something different about playing it with the black pieces which means they are more likely to win? Furthermore there are a plethora of openings which lead to alledged equality that masters utilise when they need a win. Kamsky with his London system, Yusupov with his Colle just by way of example.
It seems illogical that the first move is an issue, but in the case of the Stonewall systems, I think it is (an issue). If White commits while Black still has fluid pawns, White will have serious problems. I have played both sides extensively; move order is important. As White or Black, I absolutely want d4/d5 in place before I consider the f-pawn advance.
I must point out that these variations where one plays anything other than the queen pawn first move and follows up immediately with the bishops pawn regardless of what ones opponent does are not considered very strong. Its not an autopilot opening.