I saw someone on Facebook note the other day that he had to dig out a couple of his comics from storage for some research he was doing. He doesn't keep most of his collection at home because of space reasons. He went out to his first storage unit and couldn't find the books. So he went to the second, only to discover that a recent, localized earthquake had shifted the building just enough that he couldn't open the door to get to his books. It sounded like his collection was still relativly safe as far as he could tell, but half of it remained inaccessible.
Another friend noted on Facebook that he's trimming his collection down, as he periodically does. This time through, he's getting rid of everything except for thirty-five books. Yes, 35. I'm not 100% certain, but I believe this culling of his collection is mostly to keep them from overtaking his living space as he's donating many of them to libraries and charities, as opposed to trying to make any money from them.
Most of my collection right now resides in a storage unit as well, but that's entirely because I needed to get them (and a bunch of other stuff) out of my house to make it more saleable. In looking for a new house, I've been very keen on making sure it has enough space for me to build a comic book library, where I can keep my collection and be able to get some work/research done in the same space. The last few years, I've had all my collection in one location, but I couldn't really get a computer workstation there as well to be able to do all my writing in the same spot. I could (and did) walk up and down through the house carrying books back and forth, but that becomes tedious, especially when I'm just looking for a specific quote or other piece of trivia.
That I've been able to keep my collection like that for years, and that I can entertain the notion of creating a library in my new house, is in part because I live in the Midwest. More specifically, I live in the suburbs of the Midwest. I suspect folks along the East coast and in major metropolitan areas don't have that luxury. It's easy to see why digital comics might be popular in those areas.
I'm not married to the notion of comics as individual artifacts. I'm not in this for the collectibility aspect, I want to read the stories. Whether that comes in a pamphlet or part of a bound collection or a digital version, I don't really care. But I appreciate that a lot of comics have already been printed and, before digital comics were viable, I bought a lot of them. As comics are a large part of my entertainment and research, I don't want to get rid of them as they do constitute a part of my research. You never know when you might need to reference some obscure issue of Radioactive Black Belt Hamsters or something. And while I could conceivably replace many of them with digital copies, I loathe the idea of paying for the same story twice. My run of Avengers is woefully spotty, but I still have virtually every story in some form, through reprints and trade paperbacks. No need to buy #55 when it was reprinted in Marvel Super Action #14!
Not to mention that some books are unlikely to ever get a digital treatment. Sometimes because of rights issues (e.g. Rom and Micronauts) and sometimes just because the original creator doesn't have any interest (e.g. Mr. A).
It's important to me to have access to my collection because I refer to it a lot. The type of writing I do is inherently referal in nature, and I regularly go back to not only the comics but fanzines and biographies and other printed materials. These past several months of having my collection in storage have been difficult, and much of my research has ground to a halt. But I like my collection well enough that I don't think I'll be moving into an urban area any time soon. The Chicago burbs I can swing, but I'm not so sure I'm willing to sacrfice my collection for space reasons.