Not sure. According to the Wiki page, many claimed it did but the case was dropped in court due to lack of evidence.
Im not sure Ive had a Starforce protected game, so I can't speak from personal experience.
But, look at more modern DRM schemes. Tages and SecuROM. You see ton of compliants, and people refusing to buy due to activation limits etc.
Yet I always wonder .. Why do you need to install on more than 5 machines at a given time? You can De-Auth or get those activations back after a period of time.
I've never had a issue with either of these, and never even know they are there aside from the initial activation. Yet, you still see tons and tons of complaints about them.
Perhaps its more of the same with Starforce? More of the idea its present rather than any real harm being done.
The only thing I can really find is that many boycotted any games using it, so many devs just left it behind due to the outcry and it eventually just died off.
But from some of the complaints Ive seen about it breaking optical drives etc. , and there are a lot, there does seem to be something to it.