People just love, it's a thing that human animals do. Questioning love is like questioning your elbows, or that you sneeze. It's part of being human.
> grab complete control over their emotions and keep them in check
This is what is wrong with the concept of Vulcans (when applied to human goals). Controlling emotions and keeping them in check (which is what most healthy normal humans already do to various extent anyway) is not the same as having them not arise in the first place.