Illoai's Tentacles

Why can her tentacles be placed under turrets?? That is my only problem with this new champion because other champions can't have anything under turrets. Champions like have abilities that can duplicate themselves, other champions, or summon creatures like sentinals, voidlings, or turrets. If can have her tentacles and harass you under the turret then so should all of the champions above. Even if hiemerdingers turrets don't attack a champion under turret it is immediately shot down, and the same thing goes for malz's voidlings. If riot is going to let Illoai's tentacles get immunity under tower and let her harass people when they are obviously tower hugging, or hell even walking to lane, then so should all the champs abilities i listed above. I just think there is no logic involved here.