More likely the Return 4 issues killed more shops.  My local went nuts with Adventures of Superman, but, were able to sell through enough to cover their bills.  Then, they did the same with the return issues and went bust.  They were cut off by their distributor, after unpaid bills and had to drive to Sparta, to but directly to have anything in the shop.  They kept another location going, but shut down the store I used.

Speculation, in and of itself is what killed those stores; not any one particular title.  They were over ordering and bleeding out cash; then, when the comic didn't pay off, they ate the loss over an extended period of time, as unsold inventory.  Then, they do the same thing again and they have even less cash.  Same behavior as a compulsive gambler.

The key to running a business is cash flow, with more coming in than going out.  You need that cash to buy stock and make improvements which will enhance your business.  You get that cash by turning over inventory quickly.  The more cash you have tied up in large purchases and unsold inventory, the less solvent you are and the more dangerous it is to operate.  What most small retailers don't get is the cost of inventory and they don't do the smart thing and sell off the junk at low prices, to generate cash and get the loss off their books.  I've seen shops where you had the same unsold comics sitting on shelves and longboxes and you aren't surprise when the place has a Going Out of Business Sale.

Too many comic retailers in that era where fans first, business people second.  Sadly, that hasn't necessarily changed.

Same problem affected a lot of the indie publishers who sprang up in the late 80s, in the wake of the Turtles and other early direct market successes. Most were out of the business within 5 years because of cash flow, especially those that tried to do newsstand distribution and direct market. Comico tried that, I believe Now Comics did, First might have (definitely did with the Classics Illustrated revival, in terms of selling on a returnable basis to bookstores). In 1987 there was a massive influx of new publishers and by 1993-94, most were out of business. Dark Horse, and to a lesser extent, Fantagraphics, were the only ones with staying power. Fantagraphics had a close call when 7 Hills Distribution, who marketed their stuff to bookstores, went under, owing them a lot of money. They made an appeal to the comic community to buy directly from them, via their website, to get enough cash to float them until they could secure new distribution and other revenue. Dark Horse has always been smart (well, except Comics Greatest World, if you ask me) and kept their ambitions within their financial resources.

Left to right, starting at the top of the page and progressing to the bottom.

never!  As soon as you take off the dust jacket, it's bound to get lost or destroyed.

I don't take off the dust jacket, no. I usually either read them laying down with the book on the floor or I read them in bed, sitting up against the headboard with my knees pulled up to provide something for the book to lean on as I read. Generally omnibuses aren't terribly convenient to read though....good value, yes, convenient to read, no.

I took my dust jacket off. It will destroy the dust Jacket if I leave it on. I'm not sure how much damage will happen to the actual book without the jacket  while reading. I'm reading Teen Titans classic, so maybe this is a test case.  

I always either take the dust jackets completely off my books or tape them on so securely that they're like a second skin. Otherwise they just make the book difficult for me to manage.

Cei-U!
I summon a question of practicality!