re: Anyone else think Nixon was treated unfairly?

Think of it like sports rules and cheating.

Anything bad you do is punishable.

Things you do to undermine the electoral/democratic competitive process, while in some ways not having as much direct material harm on people, are treated as the most egregious offenses. The integrity of the game (democratic process) is treated more seriously than anything else.

I'd say burglarizing a campaign headquarters, directed by the White House, falls under this category.