Arsenal are no where near the most hated team by the neutrals in the country, most neutrals like Arsenals playing style.
Manu, Chelsea, liverpool and Arsenal are disliked for other reasons, mostly of their own making by the current/previous managers, and its all the one thing in common, bad losers, whinging.
Wenger is a terrific manager if you look at his style of play, amount spent and teams he has build his record is great. However you do wonder how a man with such vision seemingly can't see whats in front of him on the pitch on numerous instances that happen. Calling for players/ referees heads when it goes against him, only to sheepishly say he didn't see it when it goes for him and gets away with it.
Its exactly the same for Manu, a prime example of this behaviour a few years ago AF said the Worthington Cup was a Micky Mouse Trophy, suddenlty when it was the only thing manu won it was great again.
Liverpool were probably everybodies favourite but Houllier and benitez have dragged them into teh above camp, whinging players and supporters don't help. Finsishing 5th and crying to be let in the champions league and being given it, probably was the nail in their coffin as far as the neutrals go.
Chelski are a micture of the above Mourhino, wenger, Ferguson and benitez all trying to outdo eachother, Mourhino with all his mates jumping off the bench as a decision went against them.
Most people like an underdog to win, but the above 4 are seen as getting away with murder changing the rules and treating the public like idiots, thats why most neutrals dislike them, no other reason.