Very much so. Like I said before I couldn't care less if his forms and traditional stuff are "authentic" and "proper", but his self-defence videos worry me greatly.
Here's a classic example. Someone comes at you with a knife, and Jake Mace says you should turn your back on them and then back-kick them in the solar plexus. I don't know about you but the last thing I am going to do is turn my back on someone holding a knife in my direction. This is a regular occurrence with Jake's videos, where he choses the flashiest moves possible which more often than not are unnecessary and very risky. His actual advice regarding self-defence in terms of preventing a bad situation and de-escalation are fine, but the physical techniques he employs are going to get someone killed if they try it in real life.