Answer

Hello,
The source of Maimonides’ statement is in the Talmud itself: “and you shall not stray after [your heart and your eyes].”
For a long time I have found this difficult, and it is clear to me that whether Maimonides is right or whether these words came directly from the Almighty, I would not observe this prohibition (in the spirit of “By God, had Joshua son of Nun said it, I would not obey him”)—precisely for the reason you mention. But since I do have some trust in the Almighty, and also in Maimonides, I thought about it again and again, and I will briefly write here what I came up with.
I will preface by saying that Maimonides himself violated this prohibition with his own two hands (somewhat like the Radbaz’s comment on the prohibition against returning to Egypt). Therefore it seems obvious to me that this prohibition is directed at one who would obey it. Someone who is troubled by these questions and does this for existential reasons will not obey, and so Maimonides is not speaking to him. Perhaps if someone reads these books only as the evil inclination’s advice, in order to look for excuses for himself, and not in order truly to formulate a path for himself, there is room to forbid it to him. And this is also what the Tashbetz writes in Magen Avot: that it is permitted to study these books in order to know what to answer the heretic. And it seems obvious to me that this also includes the heretic within ourselves.