He definitely had some problematic opinions. Namely he thought that modern feminist and gay rights type movements were distracting from bigger problems. Though he did actually get that ideological idea from Marx who theorised that the owner class distracts the worker class with disputes over social rights of marginalised peoples to distract from the bigger problem in society (which marx viewed as the owner classes monopoly on ownership of means of production, while Kaczynski viewed it as techno-industrial society which removes people far from their natural behaviour (self reliance and sustenance) and destroys the nature which makes it possible.

Not sure that qualifies him as a “full on reactionary” though. And I’m not sure I agree with your dismissal of his writings. They’re quite thorough and rigorous. We had an entire class on them at the masters level in social theory.