Yes, but that is happening regardless. Everyone is missing out on good candidates.
Some people can't afford to go to a fancy school and don't have big companies come recruit on campus. Some people can't get certification or evening degrees because they have sick parents/kids to take care of. Some people can't do unpaid internships or make open source contributions that look good on their resume because they rely on the income from a job in retail. Some people can't do well in interviews because they have anxiety or other similar conditions.
I'm sure a lot of them are competent developers, but the reality is that there is no good selection process that tells you that with a good degree of confidence, so you have to look for other signals.
I largely agree with you aside from the final point about resigning ourselves to using these really poor signals. Recruitment is tough to get right, but we should keep improving.
Some people can't afford to go to a fancy school and don't have big companies come recruit on campus. Some people can't get certification or evening degrees because they have sick parents/kids to take care of. Some people can't do unpaid internships or make open source contributions that look good on their resume because they rely on the income from a job in retail. Some people can't do well in interviews because they have anxiety or other similar conditions.
I'm sure a lot of them are competent developers, but the reality is that there is no good selection process that tells you that with a good degree of confidence, so you have to look for other signals.