I can see your point and relate, if a shop can't keep a simple reserve list then you have every reason to walk away.
On the other hand, for every copy of Hawkeye & Mockingbird that I may have sold by ordering a few extra, I would be stuck with Young Allies, JSA All Stars, Namor copies sitting on my shelf. No business whould be ordering 10 items hoping 1 will sell well enough to compensate for the rest. You also have to factor the no returns factor, that cuts into the profit margins nicely. If Marvel & DC gave retailers Strip Cover returnability on even a small % of the quantity ordered, your Hawkeye & Mockingbirg would be in stock when you walked in, couple that with Marvel's super tight overprint policy so that they can announce that second print asap. If Marvel had so much confidence they could have printed enough extra so that when if I saw a book selling out I could rush ship some extra copies in and no one would miss out.
Sorry to anyone who thinks digital will save us, there are lots of benefits to digital and it may gain the industry some new blood. I have several friends who have downloaded comics illegally for years and now they won't even download the comics for free, due to the lack of content and the dilution of product. Thats not availability, or 2nd prints taking to long that is pure content problems. If someone won't read a book for free, what makes anyone think $3.99 in a shop or $1 online will make a difference.