I completely agree, the amount of times I have seen crews say its too difficult to fill in the ASR F is pathetic. The ASR F is critical in building an "admissible" paper trail. By not filling it in "EVERY TIME" you are fatigued you are undoing any remote chance of these patterns being flagged and sealing our fate.
Apparently its up to us anyway in case you missed it "Employees have an obligation to minimize fatigue so that they are fit for duty, and shall not perform any duty if they consider their fatigue level to be unacceptable"
Don't sign on if you aren't rested, once commercial and rostering get the message that these particular flights in question are un-crewable , we'll go back to the SAFE OPTION, a hotel and a bed to sleep in.
Don't be that guy that has the fatigue related incident / god forbid accident, be at home asleep where you should have been all along.