I'm not aware of any mainstream proponent of ID who argues for a young earth or a 6,000 year-old earth.
do a google on creationism young earth
Results 1 - 10 of about 544,000 for creationism young earth. (0.20 seconds)
That would be among the scientifically literate. But if you follow FR threads you will find the most of the people supporting ID are literalists of some stripe. Many are YEC, and many more dispute "macro" evolution.
So why are they supporting ID, and why don't ID supporters correct them?