Another factor that prevents abusing this system is that when you die, you can only transfer the skill you were born with, not any skills that anyone else has given you. So no matter how many skills you amass during your life, only one gets passed down to the next generation. For every one skill you want to gain in this manner, you require one individual who is both (1) dying and (2) willing to pass on their skill, and while the first condition is easy to meet by force, the second is not.