They haven't. Data shows the opposite. They are not the solution, but reduce the problem. The fact is that quotas have increased the presence of minorities AND productivity hasn't reduced. In some cases it has increased. So it is a fact that the people hired by the quotas is doing the job which they won't be able to if they weren't qualified. Sure, inclusivity is better than simple quotas, but if you can't do inclusivity right, quotas might work as a proxy. Fake it until you make it.