I pointed out many of the same points the Wikipedia cite gives, I was just pointing out that the Claim by Snell was excessive for the facts he had. Even the Wikipedia article you cite, points out the problem was less illegal brides or conspiracy, but old fashion and legal lobbying i.e. informing politicians how to better transportation and emphasizing bus instead of rail, providing funding for buses, but not streetcars, running ad campaigns that showed streetcars as old and obsolete, but cars and buses the wave of the future.
All of those activities are legal and most transportation departments fell to them (I even pointed out that the one book almost every transportation manager used to design highways called not only streetcars but buses and pedestrians "traffic impediments" . To truly understand how the Streetcar systems were killed off (and why so many did survive) you have to understand it was NOT illegal activities that did in the Streetcars, but legal activities such as lobbying, providing funding for buses only, providing free copies of books on how to design highways, that minimized anything but automobile traffic.
And that GM was NOT alone is this attack on the Streetcar system, Hurst input in the death of the New York Streetcar Line is well known and his push affected other cities. Cheap gasoline of the 1940s till the early 1970s was often the final nail it a coffin of a transportation system already under attack (and the public policy that encouraged cheap gas had more affect then any other single factor). The second biggest factor was the break up of the Utilities that separated the Streetcars from its potential source of revenue to rebuild when the system was do to be rebuilt. These all had more affect then GM's attacks on the system, GM's plans just made it sure that not only the inefficient Streetcar lines would go under but even the marginal profitable ones would also go under.
Thus the purpose of my comment was NOT to dismiss the conspiracy but to place it in content of what else the Streetcars were up against. The worse part was bad press by just being on the street. That build up more pressure to get rid of Streetcars then any other single factor. That build up of opposition was encouraged and egged on by GM, but again that is something NOT illegal, and thus something we must understand so we can try to make sure it does NOT happen again.