I can see the logic in what you're saying, but my concern is that using the curbs leaves things too open to interpretation to be consistent. Curbs aren't on all parts of the track, and they aren't the same across all tracks.

Really, the issue of exceeding the white line isn't a rules issue, it's a team issue. The teams build and operate their cars around a huge number of regulations. They've simply decided that this one doesn't have enough of an impact to warrant the investment. More races like Austria and they might start to take track limits seriously.

Or, this is a problem specific to the Red Bull Ring and modifying the track will prevent it from reoccuring. I don't recall this frequency of penalties occuring on other tracks this year.