There is a case to be made that administrative subpoenas can be good. They save taxpayers money, they speed up investigations, and they free up the court for more important matters.
As with all things though, these agencies should not be self-regulated without civilian and judicial oversight.
They seem unconstitutional on their face, to me. Speeding things up because the Constitution makes it too hard is a bad idea.
Save taxpayers money?
I don't think I've ever seen my taxes go down in any tangible way from all the supposed taxpayer saving initiatives over the years.
Somehow we broke the "cheap, fast, good" metric and we don't even get "good" nor "cheap".
I'd prefer good and what i'm paying regardless over some false "savings"