I recently experienced such a crew entering the plane first as soon as boarding for business class pax was announced.
That left quite a bad impression on some full fare paying pax.
An impression no doubt of the entitled, status conscious, precious little princes and princesses who seem to abound these days. Who cares who boards first? Everyone has a seat allocation, does it really matter who gets to their seat first? We could have a race on the drop of a flag by gate staff, that would work well. Perhaps with a prize to the last to board, as recognition of their politeness, after you sir/madam.
The people in seats 0A and 0B board first. How dare the hired help.