Lets have a quick review of the real world shall we -
Scola's replacing either A) Juwan Howard or B) Chuck Hayes in the starting lineup (assuming he doesn't bust). Howard is old (33 last season), has bad knees, and was never renowned as a defender. His main claim to fame is being massively overpaid for slightly above average production by a stupid GM...Chuck Hayes is a great kid, has a real nose for rebounds, and a non-stop motor. That said he's 6'6". He's also not the saviest, most skilled guy around. He's no defensive beast either (his opponents PER while playing PF is 16.5,
http://www.82games.com/0607/06HOU10C.HTM).
I don't think anyone is disputing that Scola's better offensively. I'm not at all sure that he isn't a better option defensively. Remember, having Yao acting as backup is useful. Sure Yao lumbers, but he's A) HUGE and B) he actually tries hard, unlike half the bigmen in he NBA.