The idea sounds nice, but it ends up just reinforcing cronyism. If you belong to the right in-group, usually stratified along some social injustice, you'll display the merits that in-group wants.
Solving underrepresentation issues is, in my opinion, more about changing the perception of the industry for those poorly represented groups and performing outreach at younger ages, rather than having companies hire disproportionately more women or people of colour so that their employees look more diverse. That doesn't really solve anything.
A simple thing you can do is publicly state, "we encourage women and other minorities to apply". And that's all. You encourage them. You don't have to give them any preferential treatment to pad your numbers (and I don't think anyone ever really does that, but a lot of people seem to be afraid that it happens). You just have to explicitly direct your invitation to them. That's enough to increase your hiring pool and give your company culture a nudge in the right direction. If you object to the alleged benefits of having a diverse staff, I can't imagine you would object to attracting more people to apply who otherwise wouldn't.
A further point I want to emphasise: what is merit? Who decides what is merit? If you think being nice to others has no merit (or is not "good performance"), then you may end up hiring toxic employees like Fowler's sexual harasser and then keep him around because of your merit metric. This will end up costing you good employees like Fowler.
I agree with your suggestion that encouraging women and minorities to apply, and ensuring that one's company culture is inclusive, is a good start. However, this doesn't really help with the core issue, which is that the number of women and minorities getting into the field in the first place is disproportionately low to their demographic representation. I'm not well-positioned to suggest why that is, being a white man myself, but until the underlying issues are solved, decrying meritocracy as promoting white men over other candidates is not a valid criticism.
Merit is for each company to decide for itself. I'm sure there are many companies, Uber included, that consider themselves a meritocracy but the way they measure individual merit just leads to toxic culture. Fowler made mention of a number of bad actors who were not fired because they were high-performers in the company's eyes - and this is a valid concern for companies that aim to be purely numbers-based in their evaluations. Personally, I'd say that there has to be a baseline of decency for an employee to be valuable at all, and that how someone interacts with others should be considered as a metric for their individual merit. Quantifying that, however, is a whole 'nother question.
https://www.susanjfowler.com/blog/2017/2/19/reflecting-on-on...
Nothing to do (directly) with underrepresentation or "hiring lower-performing females".