It is not a hard and fast rule (nothing is; everything is up to voters) but it is the number one reason I've heard for why some proposals aren't supported, including yours.

My proposal received more votes than any other and in terms of voted SP it is still within the top positions. So it's not a problem related to lack of support. As I stated, the Return-Proposal was moved 3.6 M SP up (over night by one single voter, a top witness), so that mine does no longer receive funds.