What makes you say that? Between being sent to prison for high treason and having his party banned, what part was kid gloves handling? Not shooting him in the head? That's how you make a martyr for someone worse to take power. He was allowed to get close to power because he was less threatening to capitalist interests.
Hitler was sent to a gentlemen's prison (Festungshaft) for high treason with a sentence of five years, but released after eight months. That is completely ridiculous for high treason. The regular sentence was life, the absolute minimum in case of exonerating circumstances (in this case most likely being right-wing, sorry, "wanting the best for his country") was five years. I'm pretty sure that he would have spent life, or at least many years, in prison if he had been a communist.