If you really want to summarize the situation quickly: GM et al did conspire to monopolize the bus industry. They didn't conspire to destroy streetcar lines: t

If you really want to summarize the situation quickly: GM et al did conspire to monopolize the bus industry. They didn't conspire to destroy streetcar lines: those were already largely failing due to decades of underinvestment. Given that bus transit themselves has now fallen (especially in the US) into decline because of persistent underinvestment, there's been a resurgence of romantic attachment to streetcars, and so the conspiracy has been transformed in popular imagination into a more sinister conspiracy than ever actually existed.