I think those saying he has solely gone for the money are a bit wide of the mark, for you as an individual that might be the case but how can you honestly say without doubt that that is the case for Burgess?
have you thought that actually people like challenges, to have new experiences when those chances come along, to better yourself (not in a pure rugby sense because that just isn't happening).
Not only does he get a nice big salary he surely knew that the toll on his body wasn't going to be anything like that in RL as many have said it'll be a good rest for him by comparison.
And one of the big perks is being able to see family members & friends whom are UK based a darn sight easier than being in Oz for 10 months of the year, certainly not a deal breaker but it's another small aspect that adds to the reasoning on the plus side.
Whatever his reasons those being critical is reflective of them as a person, you don't need to understand his motives because frankly it isn't any of your business. I watch a bit of union to catch the scores, see who's doing anything special but can't manage more than the edited highlights because for the most part it's w'nk to watch, if Burgess is playing union so what, good luck to him.