Well... opinion, so I can't push that line of argument any further.
It's not a vested interest if there is no secret agenda. Obviously, Ferrari doesn't want points stripped or money taken away. No team does. But Ferrari was also apparently bristling at being accused of violating the letter of the law when they hadn't. Note: Letter... not spirit. Many teams do their best to violate the spirit of the rules (which exists mostly to level the playing field) in order to win without being penalized for violating the letter.
Ferrari have been fighting controversy all season long. They've been actively hostile in the media against their critics and the FIA. I personally feel they deserve the criticism. But I still don't see their "sin" as being any worse, categorically, than Brawn's double-diffuser last season or Red Bull's flexible floors this season... or all the radio orders regarding "fuel saving" this season. All violate, in part, the spirit of the law, but do not violate the letter of the law. If the FIA wanted to win this battle, they should have made the rule clearer.
And they should be careful. The French Court ruling against them in Briatore's case has sound legal basis (never actually bothered reading the details till now). They can't afford another high profile case where they seem completely in the right and yet can't make their punishments stick.
Personally... the rule is useless. A more workable version is this: "Teams cannot radio their drivers during the race or send information to the driver's cars via wireless communication. They also cannot use sign boards to inform the drivers of the position of other cars. Cars and helmets will not have distinct markings, so drivers cannot identify teammates, and drivers will not be told the results of qualifying."
Silly, but that's the only way to prevent team-mates from not racing each other, or giving way to each other.