if your argument is that a cop can lie and *say* he had reasonable suspicion, we might as well not be talking.
but if you can't see that the cop in Terry had clear reason to believe a crime was about to be committed, then you have your head up your ass. there are very few things that don't have *some* amount of subjectivity to them.
for example, if you're going 55 in a 54, you're speeding. if you walk by a show one time, you're not doing anything to indicated you're going to rob it. but if you walk by 6 times while looking in, then someone you're with walks by 5 times while peering in, then someone else comes and walks by, then the three of you meet up, you're acting in a way that a reasonable (key word right there, REASONABLE) person could interpret as "about to commit a crime.