Dunno about others, but I always ask myself where these companies would be if their software was under non free license from the start. This is hostile to end users, small people an companies, not just big megacorps wanting the "steal" the code and run it as a service. Be successful in running and using Hashicorp's software, and they decide to shut you down if you are deemed a competitor.
From what I know about BSL, nothing changes for me, except some notion what "true open source spirit" is and what not.
At any moment for any reason they can declare that you your use or your business in some way competes with them and cut you off.
You have no recourse. They don't need to explain it. They can even add a product remotely like what you're building or misunderstand your product and you are screwed.
The BSL carries with it immense legal risk.