I don't think they are to be honest with you.

Sure they have the money and can probably recruit some quality coaches as a result but I would guess it's more up to the conditions and the atmosphere.  They also have the benefit of the East/West split until the final to make it seem like they're worthy of their spot (which is bullshit).

Looking at the last five finals, the East Asian team has settled for a draw away while winning at home.  The 2013 final was between South Korea and China, 2012 saw Ulsan smash Al-Ahli at home and 2011 had Al-Sadd only win on penalties.  You have to go back to 2006 to see an Arab team beat an east asian team outright, and that too was at home (and they  went on to lose the second leg and the final).

So yeah, i'd say it's the same as why east asian countries need to be wary of playing Saudi, UAE, Iraq etc. in Arabia.  It's just a terrible place to play football.