That's because I like that and only I am using that.
If it's a matter of team collaboration, certain ground rules can be set to resolve that.. like use blank lines after headings. You might be surprised but there's actually an Org mode setting in Emacs which can be configured to set how many blank lines to auto-insert after each heading -- I set that to zero.
> the fact that headings look like bullets to me make it harder to follow.
If you start using Org, it won't look like that. In fact, I use hyphens for list items in Markdown too as they work there too, so there is not too much context switching as I switch between Org and Markdown. I went through a lot of that as I was developing the ox-hugo package :)
Also in Org, lines starting with "# " are comments, which intuitively are comments in many languages. Markdown doesn't have comment syntax! I need to do stuff like below to fake a comment in Markdown:
[//]: # "comment"
So the "headings look like bullets issue" will wear off once you start using Org, and then you wish Markdown also did the same :)