I can agree that its less self-perpetuating than racism is. But the root cause of imbalances in tech is also very pervasive, as it is a product of gender stereotypes in the wider culture. Gender stereotypes are certainly self-perpetuating: young kids internalize what they learn and then perpetuate that behavior as they become older. So to break that cycle requires direct intervention to prevent shaming for girls who don't like stereotypical activities, and to allow other girls to sample things that they otherwise would not have thought open to them. A part of this intervention is to get more positive female role-models in tech and hard science fields. Direct outreach to older girls by creating (admittedly artificial) learning environments that they will be more comfortable in will help with this. These artificial environments aren't a solution, but they can be a stepping stone for girls who would otherwise be too intimidated to give it a try otherwise.