I have no problem with a government agency creating regulations in order to promulgate a law passed by Congress. The alternative? Congress becomes more of a bureaucratic red tape monstrosity than it already is. The truth is that these agencies more often than not are very familiar with the topic area and are better equipped at enforcing the law passed by Congress. Now agencies are not allowed to create laws, only create regulations that promote the laws passed by Congress.
Here's an example: Recently Congress gave the IRS power to draft new regulations regarding college tuition savings plans (commonly referred to as 529 plans). Apparently it has become common place for wealthy individuals to transfer their wealth into these plans naming grandchildren as beneficiaries but end up naming only one owner (such as a child). The real reason why this is done is so the child, and not the grandchildren, can withdraw from the 529 plans thereby bypassing a 45% tax and only paying a 10% penalty plus income tax. Congress realized they were unable to deal with the intricacies of drafting effective laws defeating this kind of tax abuse.
My point is this, government agencies have much more flexibility and ability to make sure the laws of Congress are followed by enacting regulations. If Congress is really appalled at a regulation passed by an agency, they will either exert their influence on that agency to change the regulation or simply enact a law nullifying that regulation.
In short, no, I'm not bothered at all that this happens. Whether that's legal, I do know the U.S. Supreme Court has ruled it is. Again, I'm not bothered by it since the alternative would be unworkable and extremely inefficient. You could argue it would be counter productive to a democracy.
Lead me not into temptation... I can find it myself.