One reason Triple H was moved to SmackDown is due to a scheduling matter. The schedule on Smackdown is actually a lot more convenient for him, especially considering that wife Stephanie McMahon-Levesque is due to give birth in about a month and will be taking the babies on the road upon her return to work. The regular Raw show schedule runs from Friday to Monday, so he is always on his own on the road because Stephanie doesn't attend house shows. However, Stephanie always attends the weekly Tuesday SmackDown tapings, whereas Triple H is at home or on a plane going home. When he was on Raw, they pretty much only saw each other on Monday, the latter part of Wednesday, entire Thursdays, and the early part of Friday. Now that he's on SmackDown, he can see Stephanie and the kids Monday through at least Friday. The weekly SmackDown schedule doesn't start until Saturday night, so that gives them part of another day to be together some weeks. Instead of seeing his family for parts of three or four days a week, he should usually be able to see them as many as six days a week.
The scheduling issue wasn't the only reason for the move because the SmackDown brand was in dire need of a huge new star to say the least. Also, Triple H's move to SmackDown should give the show a ratings boost when it moves to MyNetworkTV this fall.