There are people who disregard the teachings on rebirth and anything else they deem supernatural. Anyone can freely study and practice Buddhism without fully agreeing to every words of the Buddha before checking everything personally. It is actually a level of attainment within Buddhism when one has gained assurance via study and practice that the teachings of the Buddha are true. So you should not worry about your scepticism regarding rebirth. However, it should also be clear to you that rebirth is a fundamental teaching within Buddhism on which the entire path of liberation is based (i.e. without something to be free from there is no point in working for enlightenment).
"While teachers of the middle way, mind only, transcendent wisdom, mantra, and other schools may have their own assertions, the fulfillment of those intentions is the same. There is not a single thing that is not contained within mind."
(Gampopa to Düsum Khyenpa, in "The First Karmapa", KTD Pub, p254)
“If you recognize the world of appearance and existence as the mind, realize the mind itself as empty, and have no grasping at the superiority of your realizations — this is the ultimate view."
(Chegom Dzongpa, in "The Book of Kadam", Wisdom Pub, p609)