I don't need to base my opinion off of one guy's account of an incident in a blog post - I have a laundry list of my own very unpleasant experiences as a female developer to base my opinions on. I've also spoken to a great deal of other women who have a very similar list of very similar experiences. A lot of these experiences have aspects that are specific to the tech industry.

If you only have insight into industry sexism as far as one or two jerks, it's likely because you aren't a part of the affected demographic.