This is exactly how the Steem reward system is meant to work. Rewards are crowdsourced, meaning it's up to the stakeholders to determine what rewards each post should earn. No posts are entitled to any rewards, there's is no objective measure of quality that determines a post's rewards. If you post something unpopular, then the crowd will likely decide that it should not be rewarded.

No one can take away your ability to post it, but the rewards are up to Steem stakeholders to allocate in any way they see fit based on their stake.