The point is, it defines for constituents what authority members of Congress think they are using to pass a bill. As far as bureaucracy, you say that as if members of Congress are actually writing legislation and their lobbyists don't have the time to put in what Constitutional power would apple. As far as judicial review, it would be helpful for judges to be able to look at a passed law and say "Yes, this is Constitutional under the cited power" or it is not. If something is deemed Unconstitutional under the cited power, but an appropriate powere might exist, the SC could return the bill to Congress for a re-vote under that power.
Otherwise, what you are implying, is that PPACA would have passed with the mandate stated as a tax and members of Congress voting for it as a tax and having to explain that to constituents. If you think it would have passed as such, pass the bong.
