Yeah, you're right.
But I'm a little optimistic. The image being widely used for decades is a symptom, not the cause of women being unwelcome.
With it being finally banned, it seems like this is changing. Hopefully this means the root cause, misogyny in tech, is at an all time low.
Killing 50% of any one people is genocide, right? For example, the Nazis killed up to 50% of European Romani people and it is classified as a genocide.
Let's assume killing 50% of n peoples is genocide.
Since killing 50% of n peoples is genocide, killing 50% of n+1 peoples must also be genocide, else a number N would exist such that killing 50% of N - 1 peoples is genocide but killing 50% of N peoples is not. The existence of such a number N would be quite contradictory, as it would imply one could undo genocide by killing more people. Additionally, if one were to first kill 50% of N - 1 people and then kill 50% of one more people some time later, both events would be classified as genocide, since killing 50% of one people is assumed to be genocide.
Therefore, Thanos did in fact commit genocide.