In a sense yes, in a sense no. If you boil it down to "Cousin marriages have an X% of resulting in a genetic disorder" then you give a good overview of one of the many reasons consanguinity is problematic, but it is rhetoric that could also be applied to things which we don't otherwise find problematic (Like geriatric pregnancies), while also conceding legislating on grounds of eugenics.

We've long since realised that (Well in Scandinavia not that terrible long) banning people vy force of law from having children due to risk of genetic abnormalities is bad. But also these people aren't doing this to stop genetic disorders, they are doing it purely because they associate cousin marriages with minority groups that they wish to persecute. The genetic risk is a smoke screen.