Uh, what? Pitbull probably wrote his verses, sure but to assume he wrote the hook himself (and tbh, to assume he wrote every single line of his verses may be reaching) is completely naive. All of those names in the songwriting credits had a part in the writing in some way. That's why they're credited. As with most big songs like this (especially those produced under Dr Luke's watch), the hook was most likely written before Pitbull even got the song. I suggest googling some articles on Luke's musical process. You can really learn a lot about how his hits are made.