What sources have we got to go on? I don't know of any surveys which test this exactly. We have those surveys which ask questions about people's denominational affiliations, but I'm not sure that those tell us a great deal.
You have your personal experience/opinion and I have mine. Perhaps that is where we differ. I have mixed with a lot of Muslims of all persuasions. I only rarely come across people who reject many/most/all of the Hadith (I am pretty open-minded, indeed heterodox myself, and someone who isn't bound by the Hadith). Now, perhaps it's true that most don't give it much thought or are uneasy about actively challenging the orthodox thinking. Nevertheless, that still means that rejecters are in the minority, arguably.