There is more to a SQL server than the language.
For example, OLAP, distributed transactions, cluster scalability and so on.
You get the same features from other databases.
If we are speaking about Oracle, Informix, DB2, Sybase, yes I do agree.
If you aren't locked into their eco-system stay clear away from it. Otherwise you will regret it, as the licensing costs are very expensive and per CPU core (think Oracle). Better switch to MySQL or Postgres or Lucene, etc.