This is a fair question. If an average person had made the same speech at the same time in the same location, he could have easily met the threshold of "reasonable doubt" to beat the incitement rap.
But Trump's status was unique. He had access to some of the planning (either through direct contacts between his staff and rioters, or though his ability to monitor social media posts), and he helped to arrange for the Capitol to be underprotected by security. Then, when his supporters started to attack the police, he refused to call for more police (despite having the power, if not the authority, to do so), and instead went on national TV to tell the violent mob that their attacks were actually peaceful, that he loved them, and that they were special.
So, to pose your question in different manner: Trump knew, or should have known, that they were planning the attack for months? And he didn't demand more security? And he did the speech anyway? And he still urged his own supporters to march on a Capitol that he had helped to weaken? And then he refused to unequivocally condemn their behavior?
It may not meet the criminal code's definition of "Incitement", but it does meet a moral definition of being unfit for office. Trump didn't incite his supporters to start a fire; he just made sure that there was lots of tinder and that the sprinklers were turned off, then he winked at his supporters as the fire burned.