In a season where we've wildly underperformed, been knocked out of both domestic cups by January, shown absolutely no discernible or visible indication of progression, and our current run of form reads 3 wins from the last 9 (2 if you discount the loss on penalties to Sunderland), what makes you think a defeat at Arsenal will speed the process up in any way whatsoever?
Likening us to Spurs isn't exactly the most viable comparison, as every noise made by United thus far, no matter how small, has been he's here for the long haul (most recently Fergie's interview with the BBC).
Surely something has to be said for those who, despite believing Moyes isn't the man for the job, think he's going to be here no matter what, in which case no one's being hypocritical or irrational by wanting us to win? If it wasn't said so matter-of-factly - "a heavy defeat against Arsenal will help this process along" - you'd probably have got more people to step up and be honest.
Does anyone really think us getting convincingly beat tomorrow will actually change anything? I don't.