Gate Checks are an admission of failure to secure the sterile area of the airport. There are a few vectors that I can think of (others with more knowledge of these matters may add or subtract from them as need be):
Normal security lines, entrances for airport personnel, entrances for flight crew.
If the normal security lines are not being attended to properly, it seems to me that the TSA should concentrate its efforts there, rather than as a last ditch effort to (randomly) catch someone who happened to smuggle something through the normal security line. Is the person caught at the gate working with someone at the x-ray machine? Then that's where you should place extra personnel, or more importantly, get rid of those bad apples who are working with terrorists to smuggle weapons on board airplanes. That's what they're checking for, isn't it?
If the entrances for airport personnel, flight crews, delivery drivers etc. are not being screened, then place your TSA agents there.
Stop punishing the traveling public for the shortcomings in your system.