That sounds like a "motte and bailey" argument to me. It's common sense that "the good and bad consequences of regulations should be understood." That's a position that's trivially easy to defend. Libertarians usually argue for a great deal more than that: civil liberties, non-interventionism, laissez-faire capitalism and the abolition of the welfare state. But these things are not obvious simply from understanding the consequences of regulation; the arguments for them have to stand on their own.
Just as patriotic and humanitarian rhetoric is used to justify certain polices that are far from patriotic or humanitarian, libertarian rhetoric is also sometimes used to justify lax regulation, crony capitalism, etc.
I think most people who call themselves libertarian today have betrayed the first principle of libertarianism (my body and the fruits of my labor belong to me and me only) by adopting stances and definitions that are actually antithetical that principle.
Are you a Real Libertarian, or a ROYAL Libertarian? is a must read.
http://rationalwiki.org/wiki/Motte_and_bailey