The entire point of the deal, politically speaking, is to dismantle Iran's nuclear program in a way that allows Rouhani and the Iranian moderates to save face to their own people by maintaining the apparent shell of a nuclear program. So they get to claim, "we still have centrifuges, we still do nuclear research", and those claims are literally true but substantively false. In fact they're only keeping a small number of very old centrifuges that are carefully monitored, the equipment necessary to make new centrifuges is locked down with constant inspections, future imports of such equipment are highly restricted, extraction of their natural uranium deposits is carefully monitored, along with many other measures designed to make it impossible to move towards a bomb.
Ernest Moniz, the US energy secretary who helped negotiate the deal, is a nuclear physicist. US national labs employ many of the world's top nuclear experts, who consulted on the deal. When they, and most of the rest of the world's experts on nuclear physics and nuclear policy, say this is a good deal (http://www.vox.com/2015/4/2/8337347/iran-deal-good), I'm inclined to think it has some merit. Could it be flawed? Sure. But you need a better argument than "OMG it lets them keep some centrifuges".
Ernest Moniz, the US energy secretary who helped negotiate the deal, is a nuclear physicist. US national labs employ many of the world's top nuclear experts, who consulted on the deal. When they, and most of the rest of the world's experts on nuclear physics and nuclear policy, say this is a good deal (http://www.vox.com/2015/4/2/8337347/iran-deal-good), I'm inclined to think it has some merit. Could it be flawed? Sure. But you need a better argument than "OMG it lets them keep some centrifuges".