Personally, I just feel we don't have the players required. You need to be extremely confident in your abilities and technique in order to try to play through teams centrally.
You need to trust your (and your team-mates') ability to pass accurately into tight areas, and your (and your team-mates') ability to control the ball within tight areas.
Not enough of the players are confident/skilled enough. Herrera's one of the few who's willing to try a little, clever dink or turn under pressure - because he come from Bilbao, who played in that experimental style, where they weren't afraid to zip quick balls into each other at all heights and angles.
More players in that mould are needed. Being able to pass accurately from point A to point B isn't enough, if nobody feels comfortable controlling a difficult pass under pressure.
And that's what we're seeing now. Players who can control possession of a game, but don't put the ball into dangerous zones often enough. The ball seems to get passed to everywhere but where it needs to be passed.
Maybe van Gaal shouldn't be trying to force this style of play with players who can't actually do it well enough. So some blame lies with him. But I think it's a good style of play. better players are just needed. I'd say a top passing/possession side needs four or five extremely confident ball players. We see that with Bayern (Lewandowski, Thiago, Costa, Robben, Muller) and we saw that with Guardiola's Barcelona to a greater extent (Busquets, Iniesta, Messi, Xavi)
