I don't think that necessarily follows. For example, if 20% of some minority are qualified and without quotas only 5% would be hired, then a quota requiring hiring 10% wouldn't result in unqualified candidates.
That being said, I haven't heard virtually any advocates of DEI calling for quotas and they don't seem to be common at all.
We can use an actual example. Joe Biden going into the 2020 election pledged that he would choose a black woman as his running mate. This pledge excluded half the population on gender grounds, and 87% of the population on racial grounds. When you are only looking at half of 13% of the population you're going to be turning away a lot of qualified people. And we saw the consequences of Joe Bidens 2020 election pledge in the 2024 election
I never said unqualified. I used relative terms like less skilled, for example the 5% in your example that wouldn't have been hired without quotas.
The non-quota'd hires in that example, that the additional 5% displaced, are now also more likely to be of higher average skill (since you need less of them and can drop the bottom of the candidates), making a bigger disparity between the quota'd group and the non-quota'd group. Which, as I said, just reinforces any racism/sexism such quotas attempted to offset.
I don't think that actually changes anything. Lets suppose that we can measure qualification on a 100 point scale.
Lets say that there are 5 people in a minority group with a qualification of 100 and 9 people in the non-minority group with a qualification of 100. If 1 person from the minority group gets hired and 13 people from the non-minority group get hired, then a 5 person minority group quota would result in an increase in the qualifications of the people hired.
Of course in reality is more complicated since companies don't always hire only the absolutely most qualified people in a given group and it's not easy to even define objectively who is the most qualified. However, that doesn't matter to the point that I'm making which is that even a quota (which again most proponents of DEI don't want) doesn't necessarily result in hiring less qualified candidates.
In your example, no quotas would result in all 14 hires being those with a qualification of 100. Congrats, got all 5 minorities without quotas!
Now for some thing more realistic: Instead of making those 14 candidates all perfect, distribute them a bit more randomly and only hire the top 10. Without quotas you'll end up with around 4 from the minority group and 6 from the majority group. But if for example your quotas are for 50/50, you have to exclude 1 person from the majority group who is more qualified than the 5th person from the minority group to reach it.
That being said, I haven't heard virtually any advocates of DEI calling for quotas and they don't seem to be common at all.