Comment by grumpy-de-sre

Honestly it's probably just because the condition responds well to hormonal therapy. If you've got a cheap and effective treatment available for a condition it's hard to justify spending research dollars on digging deeper into it (particularly something as strange as Endometriosis, eg. where do you even start looking).

The strong genetic component also makes it somewhat unlikely that it's something we'll be able to ever eliminate completely but perhaps there will one day be targeted drugs that can stop disease progression. It's good to see more research dollars being made available in recent years.

There's a lot of other conditions that receive a similar lack of attention, for a common male analogue "chronic pelvic pain syndrome".