You are 100% right. The GP series, when it was introduced, had one feature which countered the "how can a rider who has one good meeting, be considered WC?" effect. Well, what better way to prove that the WC is the most consistent rider across the season that to make every race and every point count? A 3rd in your opening ride should not be considered a bit of a slip, to be caught up later. It's 2 lost points, lost for good. And what about "I've qualified for the semis, so why try hard to win further races" under the new system? We want riders making every race meaningful don't we? Pushing for every point, not making judgements about their likelihood about their qualification for the later stages of the meeting.
This is a fundamental mistake and ignores simple psychology. Think on. At Torun this year, we were following the destiny of the championship from race 1 and throughout the meeting race by race.