So, statistics. Allow me to fabricate a few number using some well known ballparking methods.
In November of 2010, 4,600 people contributed to GNU.
If we follow the 1-9-90 rule of speaking out, for every 1 woman who went to the authorities, 9 women have spoken out publicly, and, 90 others have not. I'm aware of 6-7 who have gone public with their accusations, and none who went to the authorities. As such, it seems safe (if likely excessive) to say that less than 100 women have been actively harassed via awkward romantic advances over the last 20 years.
So, in this scenario, not even 2% of the contributors from one month were harassed by Stallman. If we consider GNU to be on par with other software projects and say that about 30% of the total contributors for that month were women, then about 7% of the woman contributors from one month were harassed by Stallman over 20 years.
It's still too high a number, but it's not exactly a vast majority.