I don't know of linguistic studies but I imagine it's part emotional intensity as you said, but also a smaller vocabulary. Read more, and your vocabulary expands.
Plus at least in the United States, we have really conditioned young folks that they should only
have sex with people they love. This is nice in theory, but instead of raising the bar on one's sexual partners, it seems to have lowered the bar on one's loves
. The term feels cheapened, at least to me, as we keep seeing people here, over and over again (I admit this is a self-selecting class) who profess love for people when they don't even know the other person's name.
We see this from Indian users, too, and folks from Japan and China. They want to propose marriage before introducing themselves, and it's all due to hormones. They want to get into that other person's pants and so they use the term love, and they may be infatuated and attracted to their looks, but that's not love.
On the other side of it, the popularity of the expression, "haters gonna hate" does seem to encourage people to use it. It can be an empowering expression for people, to go about their business and let their own personal freak flag fly in spite of the "haters", when in reality those are just peers with differing points of view or fashion senses or sexualities or whatever. It's catchier than "dislikers will dislike what you are doing" or "people have differing styles, sexualities, political preferences, religions, sports enthusiasms, etc.", but neither of those statements are as catchy. It's as clichéd as saying, "you go girl" when what you really mean is "be brave" or "keep doing what you're doing" or "I support you".