Yes, it goes both ways. I accuse Dhoni and Sehwag of doing that from time to time too. But Boycs was definitely guilty of it (if his contemporaries can be believed). Its not about playing defensively.
Look at Dravid, his S/R is around 40-45 normally, but when runs are needed he gets it up all the way around 65-80 when needed, even if it means he loses his wicket. I wasn't alive to see Boycs, but from reading about him, a lot of people seem to think he batted for himself and to preserve his average.
Now, that might be because no one liked him personally, but I see opposing players also accusing him of this, not just his teammates. So, I don't know.
I can only speak of players I've seen, and Sehwag is selfish from time to time. Dravid I have never known to be selfish.