I don't mind that; sure, there are other RDBMS servers that support SQL as their main or exclusive language, but unless you are talking about ancient Sybase products (for which there is a very good reason for the shared branding) “SQL Server” is a clear, exclusive Microsoft product identity and not any worse of a label, say, FTP (yes, there are other file transfer protocols).
OTOH,what does bug me is when people say “SQL” to mean “Microsoft SQL Server”.