a) The argument against Stop-&-Frisk was never that it wouldn't occasionally result in a valid arrest.
Instead the reasoning if far simpler and more logical. We don't want to live in a police State.
"Any society that would give up a little liberty to gain a little security will deserve neither and lose both."
Thomas Jefferson to James Madison
b) That's why our Founders enshrined it in our 4th Amendment, article number four in our Bill of Rights:
B. O. R. ARTICLE #4: Ratified December 15, 1791
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Certainly if we turned the U.S. into a totalitarian regime like North Korea, a few more criminals might be captured.
You think it's worth it?!
Well if you think so, why don't you move to North Korea where you'll be happy?