You're right that the last thing elections need right now is for identity politics to be built into the voting process, but I think the article's premise would be equally valid if it assumed that the electorate cared more about policy and less about physical similarities between candidates and themselves.
This does suggest an interesting hypothesis, though. While innate qualities are (or should be) a poor proxy for a politician's voting record, we might be at a stage in many democracies where a politician's stated policy preferences are also a poor proxy for how they end up voting. In a "market for lemons" way, voters might feel that it is best to focus on immutable characteristics of the candidates, rather than believing a word they say.
You are correct that the stated policy positions of a politician don't always align with their voting record but innate characteristics of a human aren't a policy position at all. If the electorate paid attention to the people that they elect and if they're voting record aligns with their stated positions things would get a lot better.
At least in the United States around 80% of the federal government is re-elected every two years. At local levels there is also a similarly high percentage of turnover in just a few years time. So at most if someone campaigns on something that they do not follow through with their votes in 2 years we can swap them out. The problem is when people are voting based upon identities people continue to get reelected to office based upon identities. We see this with long standing politicians that continue to get elected while rarely voting for the actual policies their constituents want.
This does suggest an interesting hypothesis, though. While innate qualities are (or should be) a poor proxy for a politician's voting record, we might be at a stage in many democracies where a politician's stated policy preferences are also a poor proxy for how they end up voting. In a "market for lemons" way, voters might feel that it is best to focus on immutable characteristics of the candidates, rather than believing a word they say.