It's hard for an open source project started (or dominated) by a single company to shake the appearance of being insular. At this point I believe Kubernetes has major contributors from various companies, but I still mentally think of it as Google because, among other things, a bunch of the infrastructure is still Google so it feels very much like Google has dominant control. The dominant company will need to actively drum up interest and try to convince external contributors to take up the work to make it look less lop-sided.
I don't mean this as an attack on Google — getting good community governance is hard; I've also been on the dominant company side on other projects (generally not great at fostering a good external community). I believe it takes extra concerted effort.