What opinions has Bob Martin expressed that are objectionable?
Martin himself shows himself to be a biased person which he shows time and time again on Twitter. What if he were to decide who got promoted or hired for companies?
There are literally studies on this.
The fact that people have bias cannot be the issue in itself, problems occur when they are ignored and not taken in account by systems.
For example a hiring process can take in account biases and have ways to correct for them, for example by avoiding to have one single interviewer having way more weight than another, by doing blind reviews, etc.
And that meritocracy on its own cannot work because everyone is biased in one way or another. Got it.
I see meritocracy as an ideal we would like to be able to tend to, not something that has been achieved in the past or current time.
Meritocracy is full of flaws.
I do believe putting more diverse set of people into power makes a difference. Having racial diversity, gender diversity, cultural diversity, financial diversity etc. is important for having fair and fruitful leadership at companies, in gov't, and whatever other places.
I object to using the notion of a "6X difference in murderer density" among Black men as a reason why police are justified in racial profiling.
But I also object to the extremely smug and faux-engineer-rationality of "This does not appear to be racism [...] It looks more like math."
If we're expecting Uncle Bob to be just some guy on Twitter I would write him off as a simple fool. If we're expecting Uncle Bob to be a thought leader in a consequential professional field requiring deep analysis and sound judgement, that's something else.