The senate hearings are just theater. Important questions like this should probably be async - compel the companies to provide specific answers on the record.
That said, I'm of the opinion Feinstein is largely senile at this point, and wish she'd retire.
I share your opinion that the NSA's surveilance is bad, and I'd assert it's unconstitutional, but the hypocrisy/contradiction you're trying to highlight still isn't necessarily there.
The government can kill me; Facebook cannot. The government can imprison me; Facebook cannot. The government can require I pay taxes; Facebook can not.
It shouldn't be surprising when similar disparities exist on surveillance. The NSA's program has yet to be deemed unconstitutional by the courts, which is what matters.