No one is saying there's anything wrong with releasing your code under the BSL. What's wrong is that you're lying and claiming you're open sourcing your code.
It's a straw man that lets them ignore the actual issue people have.
https://github.com/ssddanbrown/Open-Source-Confusion-Cases/i...
The repo readme has other examples of sketchy cases of open source and licensing usage. This aspect (of why not just use a different term) often gets ignored. Sometimes folks say they're using it "to prevent confusion to users since they would have heard about open source" which is always an ironic self-involved viewpoint to see.