What a great idea, naming your tool almost exactly the same as biggest code quality / static analysis tool that people already use. /s

Is this the reason for this?

http://sonarqube-archive.15.x6.nabble.com/SONAR-is-becoming-...

Could be, although that was 2013 and this trademark was just filed: http://tmsearch.uspto.gov/bin/showfield?f=doc&state=4801:7o1...

I loved this site, it has been very helpful to identify problems on our site.