Suspension is a hindrance for loaded on-road touring for obvious reasons. It's heavy, it needs maintenance, unless you lock it out it uses energy that could be propelling you forward, and it ain't much use for front panniers. However, my Thorn Nomad will take a suspension fork if I want it to, and that might be useful if I ever tour anywhere that there are few paved roads.

Having said all that, I agree with cycommute. Hybrids are not "essentially the same" as touring bikes, any more than they are "essentially the same" as mountain bikes. They have overlapping characteristics, just as road/touring/CX bikes do, but there's a big difference between riding my tourer loaded and riding a hybrid with a similar burden.

What does seem to me to be true is that my tourer will do everything that a non-suspension hybrid will do, and do it just as well. The reverse is not the case, however. Which may explain why I have never felt the need to add a hybrid to my stable of bikes.