This statement is undoubtedly true.
The Human Race owes a great debt to Nuwa, and Nuwa has not gained anything from them;
She has been protecting the Human Race from the ancient past until now because they are her creations, her children, as it were.
If this were a world joined by the Hongjun through the Heavenly Dao, Nuwa could have gained immense merit from creating humanity and become a Saint of the Heavenly Dao. Then, it could be said she had received great benefits from the Human Race.
But this is a world without the conjoined Heavenly Dao of Hongjun, where the Heavenly Dao is still in a state of semi-dormancy.
Indeed, the relationship between Nuwa and the Human Race more closely resembles that of a selflessly devoted mother and a child who keeps disappointing her.
Yes, disappointment.
The Holy Mother Nuwa would speak in such a way probably because she is extremely disappointed in the Human Race.