most foreign policy experts disagree with you
Classic argument from authority. Can you tell me why you think my reasons for thinking the deal is bad are wrong?
Sure.
Iran is funding terrorist groups. Lions and tigers and bears, oh my.
Iranian officers are on the ground in Syria, leading troops and stuff. OMG run to the hills!
They call us "The Great Satan." Tremble in your boots, 'Murica!
And what was the other one? Oh yeah. Centrifuges.
Well once upon a time there was a country that didn't just fund terrorist groups, but actually conducted large scale proxy wars against US allies and interests. They had client states in Eastern Europe which were basically puppets of their regime, all armed to the teeth and itching for a fight.
They sent their officers (and whole lots of weapons) to our enemies and encouraged their judicious use. They placed spies in our government, including our intelligence services.
They didn't just call us names...they had as their main goal the destruction of our entire system. The whole idea behind not just the US, but the West in general was one they tried very hard to stamp out.
And they didn't just have a few centrifuges. They had at peak capacity at least ten thousand actual nuclear weapons pointed right at us. Not stored away just in case, but loaded onto planes, on top of missiles inside of silos and submarines, and all ready to be launched at a moment's notice.
There was even a time when they tried to park a whole bunch of nukes just 90 miles off our southern coast.
Yet despite all this, we were able to negotiate not just one, but several nuclear treaties with the Soviet Union. Not only did we not start a nuclear war, we actually managed to reduce both arsenals and are to this day slowly dismantling weapons.
This deal with Iran gives the P5+1 far more leeway over their nuclear program than the US ever had over the Soviets. It goes farther than any treaty we had with a country that actually pointed nuclear weapons at our cities for decades. This is a multi-lateral agreement between six nuclear-armed nations and one that isn't.
Iran didn't win this round. They capitulated.