True. But SF is full of such contradictions. Many advances in science and technology have spin off effects that lead to previously unimagined applications. The fact (in universe) that one can teleport matter (and living matter at that) should mean that something simpler like replicators should easily exist in the TOS era long before TNG. And I argue they probably do even though they're called processors in TOS. It also argues why they can so easily manufacture what they need when such items would not likely be stored for any forseeable purpose. The same applies to antigrav tech. If you can generate artificial gravity as well as manipulate gravity on a fine scale (such as with the handheld antigrav devices) then you most likely can manipulate antigravity on a gross scale. It's for that reason that I've long thought of the ship's (and shuttlecraft's) impulse drive as actually being antigrav generators.