I don't think it can be fairly described as a better Markdown. One of the design requirements for Markdown was that it wouldn't look out of place as a plain tex

I don't think it can be fairly described as a better Markdown. One of the design requirements for Markdown was that it wouldn't look out of place as a plain text e-mail or usenet posting. This would stick out like a sore thumb. That's not to say Stick is necessarily worse than Markdown for all purposes. But it is worse than Markdown by this criterion.