Bluespec has a strange story: initially it was developed like Clash, as a subset of Haskell that could be translated to a HDL. However its users hated the Haskell syntax, so the Bluespec designers added a layer of syntax on top to make it look like more a HDL, and they also downplayed the powerful type system for adoption.

Since then, Bluespec has not become too popular, but Haskell has. Clash may have a chance.