Bazel has a lot of things "missing" that had to be cut out from the OSS release. Things like grpc rule sets are extremely fragmented right now. It's a bit of A saying "the B team should maintain the rules" and B saying "the A team should maintain the rules". As such almost every single language has inconsistent support for everything: code coverage, protobuf, grpc, external dependency management, IDE integration. Also because there's no stubby, sponge, or other cool internal tools a lot of the benefits from blaze as a system are not externalized.

Also, the docker support in Bazel is pretty "different". It's not bad, but it's not immediately obvious to newcomers how this is meant to work.

It's getting better every day though.