I'm pretty sure that most guys in China go to the massage expecting 'full-service'....
I remember a time in the HI Hangzhou when there were two nice young girls who were about to give two old Russians massages. They were very excited and clearly thought they were going to get a 'massage' from an 18 year-old girl. Suddenly, the girls ran out of the room complaining to the manager in the local dialect, and the Russians were swearing in Russian. It was funny, but I think there was a bit of confusion.
I almost think that the term 'legitimate' should be used to describe the 'other' kind of massage. Especially considering that probably more than 50% of the establishments will offer those services at a price.