This interpretation of his comment is... generous. I agree that there's a legitimate point around wanting your donation to go specifically to browser development and not overhead or other side-projects, but it's pretty clear that he was using the word diversity contemptuously.
Edit: rather than trying to read OP's mind or surmise what they may be thinking, I'll give my own experience on this. I have seen companies spend money on diversity as lip-service, or targeting groups that don't really aid diversity much.
As much as I support female/LGBTQ/race rights and diversity, I suspect many companies I have been a part of would have got a better number of "units of diversity per dollar spent" had they spent money on people from lower socio-economic classes, or countries with poorer education/access to facilities (or maybe combined with the previous groups; I suspect the middle+ classes of female/LGBTQ/different ethnic origin groups are far better catered for than their working class counterparts).
But perhaps people don't consider social class or country of origin diversity? Perhaps "we hired lots of underprivileged people" doesn't give as much political capital? I'm not sure.
Sometimes it seems to me that whereas in the past we had Churches in a privileged position, telling us how to behave, that we now have NGOs doing the same thing.
For example there was just last week a report in the UK about how employees in oxfam shops had sign NDAs in settlements so that the organisation would not get negative publicity for not practicing as they preach.
It's very perplexing that you make this conclusion as a legitimate opposition to diversity.
I think diversity is just being used as a proxy for "social do-gooding, rather than tech do-gooding" and the commenter feels the former is not the thing s/he cares to support. Which is fine! I choose not to support all sorts of nominally good things. Lets not witch-hunt people for caring about different things.