No, consulates cannot give a work visa, Karta Polaka, or anything else to a Polish citizen because he/she has the RIGHT to live, reside and work in Poland. The citizenship petition is the only option, to declare his/her rights with the government.
You really are trying to argue a point that doesn't exist. Those without clear proof of Polish citizenship have no right to live, reside and work here, which is why the permanent residency through Polish descent option. It's the mechanism that's often used by Polish-Americans that retire to Poland.
Incidentally, consulates issue the Karta Polaka. You really ought to learn something about the laws in which you claim to understand.
The problem comes when someone is claiming citizenship through a grandparent, or great-grandparent, and there is some problem finding a document.
Which is why permanent residency is the option provided to such people that can prove that they are of Polish descent, but cannot prove it through paperwork. Incidentally, you cannot claim citizenship through a grandparent, as the line must be unbroken.
Those who never had to prove that claim clearly don't understand.
Those that actually understand the law know that the law provides for everyone of Polish descent as long as their ancestors had a link to Poland in some way. In the OP's case, permanent residency will be easily obtained to facilitate their legal stay in Poland.