Just my personal experience, but American kids are taught cursive in elementary school (around age 8) and then basically told not to use it in favor of the print lettering they learned first.

Schools require all assignments to be written in print, and I can't remember the last time I saw cursive "out in the wild." It's just not used in daily life unless you make a habit of using it in your personal writing/notes. The only time it ever comes up again in American schools is where certain statewide exams or college applications or something will require you to write a paragraph in cursive and then grade you on the quality of your cursive. The emphasis is put on the shape of the lettering, not the speed vs readability of the writing. So for most people, their experience with cursive is being taught a skill they're not supposed to use as a child, and then being judged for not using it almost a decade later because being able to write in it is supposed to make you look better for college admissions or something. Hence the hate.

Most Americans generally write in something with some degree of the style of a cursive script but with clearly defined and separated lettering, like D'Nealian print. But our society heavily favors print writing in basically all facets of life and "true" cursive largely feels like something you pull out for special or formal occasions - like writing the annual Christmas card to grandma, or when you're printing up wedding invitations or something.