Question about Copters and Non-projectile but still Targeting Defenses

Copter flairs are meant to distract defenses that target enemies individually to distract those defenses, but I noticed that this only seems to apply to defenses that use projectiles in particular; defenses that use hitscan (Beaming Blossom) or direct attack (Wisp Den) ignore the flairs and attack enemies normally (including the copter).

So my question is: Is the fact that only projectile-based targetting defenses aim at copter flairs a bug or intentional?

It seems odd to me that the determining factor in which defenses are affected by flairs is "do they deliver attacks via projectile" when the theme seems to be either "distracts single-target defenses" or "draws defenses' fire". Why is hitscan immune to flairs and but not a harpoon?

I think the idea is that the projectile-type defenses act as "heat seeking", which is what IRL flares defend against.  Flares are typically deployed in response to a projectile being fired, so after the attack has been initiated.  This would explain why an instant attack like Beaming Blossoms would not be fooled.  As for wisps, they wouldn't be heat-seeking, as they return to base after the job is done.

Why a harpoon is is considered a heat-seeking projectile or the fireball can track a heat-signature that isn't itself are valid questions for someone else to answer.  Perhaps the Squire is way more advanced than we give him credit for

That seems a fair enough framing. It just struck me as possibly a bug from a mechanics design standpoint. Thanks for the insight.