In my general collection when I was younger I did not shun them if they were what was available (or if there was no affordable alternative). These days I tend to be more specialized and my stamp collections are generally only mint. I was never really a fan of sand dune or eastern block material (2 of the biggest sources), with the exception of Czechoslovakia.
This all said, I at one point considered developing an exhibit on the history of cancelled to order stamps, so there are lots of different ways to approach the area.
The history of CTOs is an interesting exhibit topic!
Being a beginner I’m quickly finding out what I like and don’t like. Even the postmark.
This is a good thing. The “world” is a big place. Focus is helpful in directing collecting efforts!
CTOs are sometimes the only way to find a stamp. In the Eastern Block countries, the lowest value of a set was often printed in much smaller quantities than the rest of the set. If you look at the Scotts Catalog listing, the lower values are often in italics as they are hard to find, and infrequently sold, unless they are CTO.
You can give them to me if you like!
I often find mint stamps to be rather boring, and you really don’t want to get caught up in the ‘unmounted’ trap unless you have very deep pockets! I do however appreciate that everyone has their own style of collecting, and many collectors prefer the clean crisp look of a well centered unused stamp with strong color.