The degree of offense-taken, doesn't necessarily reflect the validity of the thought. How a message is received by society, is obviously dependent on the society of that culture. Those philosophers you mentioned, were received in entirely different time periods and cultures. Saying Peterson's message is worse, because more people are offended today, than probably offended in 400 B.C. by Buddha's message, is completely ignoring context and not really a fair criticism.

Peterson gets a bad rap, by people sensationalizing his message and then labelling him as sexist and transphobic.