I mean, we charge people for hiring a hitman, or shooting at someone and missing, even though in both cases nobody is necessarily harmed. 20 years may be excessive, but I'm not sure 'was anyone actually hurt' is a good sentencing guideline either.
The potential for harm, body and property, combined with the complete disregard for safety (aviation and otherwise) and federal aviation laws/regulations, from someone who had a high level of training (as required for all private pilots) makes it really hard to excuse.