While I agree that it shouldn't be easy to get casually, I feel it should at least be feasible for people who just no-life grind the thing during the entire Event to max either the Eidolon or the weapon. The game relies on so much RNG for getting any other components to your squad, it would make more sense balance-wise to allow people who are willing to work for it some modicum of control over their team with Events.
I have two accounts doing the Expert event only every time stamina allows, and I still can't foresee getting more than two copies each of the Eidolon and weapon by the end of this. It's barely different than if I just played a few times a day, which strikes me as peculiar.