The main reason is that he's no real story other than being an Australian. Moneymaker had the "name" that all the news services picked up on, and he got there by winning a $39 satellite online which was a first. Let's not also forget that because of the online entries that year, it set a record for the biggest WSOP ever, as well as the prize money was exhorbitant compared to prior years.
When Raymer took it last year it was also big news because of A. He won a satellite at the exact same site (Poker Stars) that Moneymaker did, a parlay that boggles the mind when you think about two poker players winning the whole enchilada back to back from the same site, and not known professionals.
B. He took down a $5 million dollar purse C. Wearing those glasses, and having the nickname "fossilman" and using a fossil for covering his cards, was more newsworthy fodder for the news outlets to pick up on! D, The big win by Moneymaker brought more attention to the WSOP.
Probably the biggest factor in the WSOP getting so much attention were the above two winning after qualifying in an offshore satellite. This gave every Joe Blow amateur a "hope and prayer" that they too could win the big one at some time in the future. Joe Blow isn't going to fly in from Kansas and lay out 10 grand to enter the tourney. Joe Hachem did that very thing, although I believe he had some "mates" taking a piece of him, so we probably won't know how much he really wound up with.
As far as tipping goes, like someone mentioned, money is witheld from the prize money to tip the dealers. If a winner choses to add more to the pot and be "george", that's up to him. Australians are not known to be good tippers, and it could be he felt he already met his obligation with the money witheld from the prize money. Let's not forget, because he wasn't an American, they withheld something like around 35% of the prize money according to IRS rules. If he had partners like I was led to believe, they probably put the "kabosh" on subtacting any more from the prize money that was already seriously depleted. Let's face it, with the IRS take of $2.625 million taken out, AND "only" a 7.5 million payout from an expected 10 million payout, would cause anyone to think twice about subtracting one more dime from the prize winnings! Especially since the dealers were already taken care of. They were already making 4-5 times the amount they usually make dealing per day, so it wasn't like they were starving!