why is saying "I love you" so serious?

Being able to say "I love you" early on in relationships platonic and non platonic needs to be more acceptable.

I've read All About Love & Salvation by bell hooks (my queen) but ive never finished it but my revelation for this initially came about when I felt myself forming a crush on someone, sounds childish but I felt like saying I love you to them or imagining myself saying it (:p) to them but then I realize how people frown upon saying I love you quite early because of being judged, lovebombing, and or fear of being vulnerable. 

I know myself as I struggle to be vulnerable, part of why Im scared of relationships, but this type of being vulnerable is disallowing you to feel emotion. 

Back to tying my connection of saying I love you to ABL by bell hooks, I feel like saying that you love someone needs to be more often. the more you allow yourself to feel i feel like you become happier.

Anyway, saying I love you needs to be more acceptable like why does it have so many circumstances?