I don't know about you but I have way too many ideas. Some are good, most of them are terrible, and some of them are downright evil. It often takes a quiet mind to see which is which and not talk myself into indulging bad ideas.
For me it's not even that I have bad ideas that I find problematic about my thinking (though I do of course), sometimes they just hurt. Kinda like how you might walk around and stub your toe and now you're like, ouch, this is frustrating, and an unreasonably intense pain for such a minor and commonplace injury. In the same way, sometimes I'm minding my business and a painful thought pops into my head and it's like, no thank you, I don't really need that. (A stubbed toe is also a good estimate for how much they hurt.)
Sitting and just sort of existing for a little while without thinking (to the extent I'm able to refrain from thinking, which varies) keeps me grounded in the world beyond thought. If you forgot you had an entire body and thought you were just a foot, stubbing your toe would hurt a lot more.