Seriously, there have been many instances where someone commits a crime and there is a significant chance that the perpetrator would be considered a martyr by their followers if prosecuted. Like Charles Manson, or any cult leader for that matter, or many people who have been charged with terrorism. In those cases the "martyring" concern didn't give anyone on the prosecutor's side any pause.
Besides, to his die-hard followers, Trump and his enablers are already martyrs. We've crossed that rubicon. Holding them accountable for their crimes isn't going to affect that either way. Anyone who raises the "martyring" objection is just trying to allow Trump and the Trumpies avoid consequences for their criminal behavior.