It's like the US tax code... it is insanely complicated and in a lot of ways doesn't serve the public well (because rich folks can use the complexity of it to escape taxation), so it's easy and popular to say let's just get rid of it and start with a new, simple tax code.
The problem is it got to be the way it is for a reason. We want to incentivize people to own homes and buy electric cars and a thousand other things, and we use the tax code to do that. If you tear it down without a plan on how to keep incentivizing all the things you want, you're going to end up with some undesirable results that you then have to fix.
It's fine to say let's throw it out and start over, but if that's as far as your plan goes then it's pretty lazy.