I'm sure they do think that - the question is whether the opposition get an increase % performance higher than our players. It's impossible to answer but my eye test tells me that when we have a big game and a huge away followings we crumble. Games against Preston, Wrexham and Newcastle for me aren't comparable - PNE was a local derby in the first half of the season (which we lost), Wrexham we where favourite's and didn't crack but ultimately where playing a L2 team and all of the pressure was on the opposition for the Newcastle game.
There's a reason playing at home is considered an advantage. The Sheff Weds players described it as a 'like a home game' and our Manager said 'a big away following has an impact but we won't use it as an excuse' (whatever that means). In my opinion there's absolutely no argument that in a potentially league-defining game giving the opposition 7K fans has a net-negative effect on our clearly poor-under-pressure players.