don't put dark matter in the same boat as relativity. People question because there arre obvious (to a physicist) problems in modern physics. There are no obvious problems in thermodynamics, so if you want to question that, then the burden of proof is EXTREMELY high. This is especially true given that TD rests upon a RADICAL statement that goes something like this "more probable things are more probable", which is reallly pretty hard to dispute.
Anyone who actively disputes TD without showing the next Nobel prize winnign theory is a quack, plain and simple.