Trump is indeed very bad and largely responsible for this whole criminal mess. But these people are being tried for their own criminal actions.
As for sentences, only a few of the worst actors, like Proud Boy & Oath Keeper organizers convicted of seditious conspiracy, received sentences of over a decade, which will probably be reduced by parole boards if they show remorse in prison. The vast majority of the more than 1,000 charged for rioting and invading the Capitol, violently confronting police, or just trespass and disrupting a central government activity, received much shorter sentences. A few were genuine criminals like one receiving 10 years in prison, having previously been convicted for 38 felonies! Most admitted their guilt to felony crimes on Jan. 6th and received fairly light sentences. Some, like the “antler horn” nut is out of prison already.
The video evidence for these flagrant crimes was so extensive there was little need or possibility for “plea bargaining,” another major factor. Of course the very nature of these crimes were that they constituted a threat to the peaceful transfer of power and to the life and limb of police, as well as of our people’s elected representatives.
The prosecutors and the state itself were rightly, in my opinion, sending a clear message — to those willing to hear — that any violent obstruction of the electoral process will not be lightly forgiven in the future.