Any system can be broken if you choose to break it. If [thing A] makes the game too easy for your tastes, then don't do it.
@ForceStealer will relate to the above statement.
I think that games should be designed with the awareness that a considerable portion of gamers (especially on their first couple of playthroughs) will take the path of least resistance. Of course, what is considered "resistance" depends on what your goal- and sought-after-reward is.
Whenever I replay the first disc of FF7, I have a choice to make: Get Aqualung and Trine or don't get Aqualung and Trine.
My goal is to clear battles as quickly as possible, unless I'm specifically stalling battles to grind some limit breaks or steal items.
Aqualung and Trine are overpowered and not too punishing in terms of MP consumption (the latter especially so). If I spam Trine/Aqualung, battles will be over in less than a minute. If I don't spam Trine/Aqualung, battles may last 2-5 minutes.
As the playthrough progresses that's a lot of battles with a looooot of needlessly wasted time if I DON'T spam Trine or Aqualung.
But if your goal is to create your own fun, rather than to simply clear battles and gain EXP like the designers intended, then you will abstain from using Trine and Aqualung. You may even abstain from the Enemy Skill materia altogether. Some gamers have more of this mindset that it's up to them to
build and
create the fun, rather than following a path of least resistance to success.
The psychology is of course a bit more complicated than this. If my goal was to simply clear a game with as little resistance as possible, I would have played FFVIIR on Easy mode. Why didn't I? Because I would feel less pride and reward from clearing it on Easy than I would on Normal. There is this ingrained sense of pride and showing that "you can deal with it" when you select higher difficulties on a game and even skip the lower difficulties altogether. In this example we have the balance between the reward of a challenge and the goal of clearing the full game.
In the case of OG though, I feel no pride and no reward from skipping out on the Enemy Skill materia, especially if I didn't set out with this challenge in mind from the very beginning. I am going to speed through battles (for lack of a fast-forward button in case you are playing on the PS1) with Trine, fully aware that I'm saving time in a battle that'd be easy to clear anyway. If the game punished me for using Trine, then I'd stop using it and start looking for other strategies.
For the same reason I never play Fort Condor without the easy-to-win glitch. There's simply nothing stopping me from doing that exploit. Extending the battle has no reward in it, especially after all these years when I already know that I can clear the battles the intended way.