Without its main stab move it becomes weak. Its like using Metagross without Meteor Mash aka retarded and even more set up fodder. The paralysis rate is also a vital factor in it setting up and providing team support.
Lets see, Heatran is moot since it cant do anything to you, Aero cant touch you after you curse due to lack of no stat up move itself so cursed body slams win against it in the end.
Gengar, Rotom, Azelf, Zam, Cress, Jolteon and Jira also moot. They either cant do anything to you or lose to fire punch/your other moves anyway.