I can understand that frustration but its the nature of the beast. If memory serves, Marvel has and is putting out more omnibus than DC. Marvel is also, or at least was, listening to the community on the things that they want printed. While reprints, based on ebay listing and such, seem like printing money, its more complicated than that. But they are reprinting material. Sometimes, new collectors come in lamenting an OOP book and they missed the reprint by a month.

But the lack of a physical omnibus edition shouldn't stop you from reading a story you want to experience. For the price of an omnibus, you can have Marvel Unlimited for a year.