Yeah, thread starters are the ones who have to remember to mark answers as helpful and/answering the question. I'd encourage thread starters to be generous with the "helpful" ranking and reward people's intention to help.
The one case this misses out is folks who eventually work out the answer themselves and share it with others; that's really valuable stuff, and the forum system can't score it.
Regardless of any artificial measure such as the forum points, we here at Ghost HQ do appreciate the effort everyone makes who takes the time to return and help others (and we also really appreciate the suggestions people make, even if the nature of product release cycles mean the results aren't immediately apparent).