The key difference being that he left for a new challenge that was helping build a new club from the ground up and proving he could be a great player in a poor side rather than people just assuming he was a great player because he was in a great side. He got the big bucks but I personally don't believe that was his main motivator. He's also quite a private guy by the sounds of things so playing in QLD was always going to help him stay under the radar.
If money wasn't his 'main' motivator he wouldn't have Pickers bargain hard on his behalf for 10 million over 5 years between October and December of 2009. McKenna let it slip in a presser that ablett initiated contact (not the other way around) and let it be known in no uncertain terms that he was serious in coming to the GC....IF THE PRICE WAS RIGHT hence why it took months to come to a protracted contract agreement.
Take into consideration that this was just weeks after Geelong had won a Premiership which makes it all the more damning.
Trust me he would not have left Geelong if it was only 10% - 20% increase in his salary, it had to a substantial amount (an approximate 140% increase) for him to sign the dotted line to play for the GC.
The challenge of leading a new franchise, stepping out of his snr's shadow, getting due recognition etc... was all smoke and mirrors to make him look less of a mercenary but that indeed he was and still very much is.
I won't bore you with other details that are also damning about his defection but it kinda irks me when non-Geelong supporters give ablett a free pas for his merc ways just because he comes across as a lovable goofy goodie two shoes dork so I felt compelled to give my 2 bobs worth.