Academia is a very very very competitive career. Things are really rough in the years before you get tenure, but once you do get that tenure, academia is one of the best careers out there. Sure, the pay isn't the highest, but the lifestyle is really good.
Publications means everything for an academic, aiming for those A* journals to rack up top publications is the way to climb up to professor (and tenure). Hardwork and determination certainly does play a role, however, since everyone in academia has those traits (you wouldn't be in the field otherwise!), I would say more comes from luck and a bit of politics. Publication in A* journals is almost like a gamble, and having connections such as knowing inside editors/referees in your area play a big role in getting those publications.
So no, certainly not, hardwork and determination are necessary conditions for success in academia, but certainly not sufficient.