I'm sure that's part of it, but this truly is a no-win situation for him. If you're not seen interacting with fans, people accuse you of not giving a damn. If you are out and interact with the core fans, people accuse you of only doing it for posturing and so fans cut you some slack.
Personally, I'd rather have the former and have it potentially influenced by ulterior motives. It demonstrates at the very least that he's not so arrogant that he feels above interacting with fans. It also demonstrates that he has enough personal interest in the parks to carry on sincere conversations with serious fans. An executive's breadth of Disney knowledge is often very different than a fan's, and some executives could easily embarrass themselves in conversations with fans. Those executives probably have good reason to avoid fan interactions so they aren't the subject of a 33-page thread on Micechat titled, "OMG, Park VP ________ Didn't Know Mine Train Thru Nature's Wonderland Was An Attraction!!!!!"
Look at it this way: if someone is in his ear telling him this is a good PR move, someone has been in the ear of Phil Holmes and Meg Crofton telling them the same things. Yet, they ignore the advice and are only on hand for occasional park events, and at those events they come across as plastic-y, canned, and without a genuine passion for the parks.
It's not a critical function of their jobs to be in the parks interacting with fans, but which type of executive would you prefer, regardless of ancillary motives?