There's like a mountain of scientific research that shows seeking and promoting diversity does improve the quality of work and environment.

Pointing out how diverse a workplace is, is certainly a lot less alienating than talking about how you don't have any female developers because they are less qualified ("lack thereof") than the male members. This company is basically saying their hiring process is perfect and it's everyone else's fault they're failing on something which does materially improve their workplace.

Companies are always hiring based on qualifications, it's about whether you take the effort to find women who are as qualified if not more qualified than the men.