I think that it could be argued whether or not he was "bad" but he definitely wasn't the best.
The biggest arguments for John Adams as a bad president:
1) He acted too much on his own beliefs and didn't go along with any party. Didn't go against Washington's wishes and enter war against France, which a lot of people disagreed with.
2) The Alien Acts made it easier to deport foreigners, and made it more difficult for immigrants to vote. The sedition acts were basically a form of censorship that prevented people from saying negative things about the government.
3) He was not as religious as many other politicians at the time, and is famous for saying that the United States is not a Christian country.
Basically, he did things based on his own beliefs and didn't go along with any one party. This caused both parties to hate him, and some could say that it led to the death of the Federalist party since they were without any real leader during this time.
They thought the government should own railroads and telegraph lines, instead of private businesses. They also wanted a free silver currency, instead of the gold based currency that was used then.
