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.
Yep open source is used as a marketing. I doubt they'd gain much adoption if it started with BSL at first place.