I am not completely sold on the idea that pure equity is a good thing. Different cultures value different customs, different sports, and different professions etc... so it makes sense that not every group is reflective of a perfect racial/cultural/religious/gender distribution.
However, there are certain outcomes that one can assume are universally desired (e.g. living longer, living above the poverty line, living in safe neighborhoods etc...). When there is extreme inequity with respect to THESE measures, when you know it isn't be choice that there is a maldistribution, there must be a 'systemic' bias. That doesn't mean that everyone who isn't negatively affected is to blame for those who are (at least not in my opinion), and it doesn't mean that the whole system needs to be torn down (at least not in my opinion). What it DOES mean is that there is work to be done.
Regarding microaggressions... I try my best not to offend, but also try my best to get offended. At a few points in my life, I have experienced some really ugly bigotry vis a vis religion, and have also encountered a lot of well-intentioned people who say something 'offensive' without realizing it (i.e. a microaggression). I don't fault people for confronting others over microaggressions... but when someone's heart is in the right place, I have trouble bringing myself to say something -I never liked getting offended, so I choose not to unless absolutely necessary.
Is implicit bias really a thing? I don't know. The idea is certainly plausible, but whether your score on a computer test reflects anything tangible is up in the air from my point of view.
@Chartreuse Wombat I would propose that an absolute belief in the IAT is no less defensible than an absolute disbelief.