The problem is that the process for rolling back a regulation like that is still governed by the Administrative Procedures Act, and requires some reasons, notice and comment, etc.. If you just say "it's gone", a court will slap it back into place.
The exception was some regs passed very late in the Obama Administration for which there was a special statutory procedure to revoke.
Yeah, Buttcrack Hussein was allowed to write his own laws but it’s a travesty for Trump to do his job using tools that he legally has. It’s appalling, it really is.