The beauty of free market is that it can create markets where there otherwise would be none. Once you normalize lobbying in your society, possibilities are virtually limitless.
You make it sound as if the government is just dying to simplify this stuff, but Intuit won't let them.
Intuit lobbies in its self interest. There is nothing wrong with that. The damage is done by the politicians who listen to the lobbying effort and play along.
Pretending like the only thing stopping them is Intuit is pretty disingenuous. All the handouts to various groups (homeowners, parents, college grads, etc) would go away under a simpler system. You're going to be the congressman to tell home owners in your district, you know, the ones who vote frequently and donate money to campaigns, that they no longer get to deduct their mortgage interest and property taxes? Very, very doubtful.