Sorry, I should have made my terms more clear...
"Reusable" refers to TMs you can buy more than once - those at the game corner, through the Celadon Mega mart, or (in the case of Emerald) Pickup.
Jynx gets the Ice Beam through a TM, but not through level-up. So the argument of "you need to buy that Thunderbolt" could not be used if you're going to give Jynx a pass.
And aside from the "efficient game", it is sometimes preferable to save the one-off TMs for battle use (yes, we still do link battles in my area once in a while). That is why I don't just spend the TMs early in the game to move through much faster - I save them, and restrict the use.