I don't know if that's gaming the system. Hell, I remember as a kid solving a puzzle on TV with NO letters revealed. The category was very specific (landmark) and just by seeing the letters up there, my knee jerk reaction was "The Washington Monument." And once you think see something like that, it's hard to un-see it until you're provided with information to the contrary.
Besides, so much of the show is gameplay to begin with. Category is "what are you doing?"? You've got an -ing word up there. "Things?" Since you know it's plural, S is even safer than it usually is (and if there's a three letter word in the middle, it's probably "and.") "Occupation"? Guess R. "Title" and the first word is three letters? 9/10 times it's "the." It's no different than figuring out the basics of any game show.
They only have, what, five or six puzzles a night. 200 nights a year for 30 years or whatever. Seems impossible to me that they can't come up with unique puzzles that don't involve random BS words thrown in. My guess is Pat and Vanna's HGH budget has gotten so expensive they had to make the show harder to win.