Do car manufactures add more plastic crap and computer modules into their cars as a way to deter people from repairing their own cars? ?

Scotty Kilmer answered a question on his channel and said that it IS one of the reasons why manufacturers do this. He also said something about these computer modules were put into newer cars not because they need to, but because manufactuers can put them there to deter people from repairing their own cars. He also said in his channel that many people from within the automotive industry hate him because he keeps pointing out the things car manufactures do not want the consumers to know. 

Also, is there such a thing as "death threats" within the automotive industry for people who think like Scotty Kilmer?  Because I do not want to start my own channel if people within this industry will threaten to kill me by making DIY videos.  

Who is this other Youtuber who told viewers that a plastic cover over the ignition coils is basically a message from the manufacturers telling people they are idiots.