Wasn't the tax pretty much targeted at them only? I think it was aimed at companies with a minimum number of employees or income. I forget which. For all we know they promised extra charitable donations to get the tax killed.
They will come up with something else. Politicians never run out of things to spend money on.
IIRC, yeah, unofficially they were looking at the deep pockets of them and Apple, but also IIRC, it would have affected "smaller" big business in the area as well - those who might not be able to shrug off the tax as easily as Amazon. Plus the usual trickle down of redefining what a "wealthy" business is so that pretty soon, they're charging a head tax to everyone with more than 50 employees, because they can.
Or way, way less. Again, IIRC, it's currently greater than $20mil GROSS. I think it's possible, depending on what they sell or provide, for mid-sized businesses to potentially meet that gross, while having a much, much smaller net income.