At least in theory.
At this point the argument hits a junction. To ask if comic stores help or hurt the comic industry also requires the question of whether or not they are really necessary. I believe the two points go hand in hand and can be answered in tandem, although they must be done in the order of their asking.
I've been reading print comics weekly for some time now, my personal experiences taking me to shops from sea to shining sea as well as abroad. In my travels, I am sad to say that the businesses I have entered, much to the detriment of the comic industry as a whole, have rarely been worthy hosts to my beloved heroes. Much like the American film industry, comic companies do not have direct control over their primary distribution agent, i.e., comic shops. There is no standard of behavior or quality control that can be exerted. Almost every Wednesday Warrior I've met has a comic shop horror story. Mine have ranged from filthy holes in the wall to condoned alcohol consumption that borders on abuse. Worse than the actual store layout is the dice roll of person inside.
I once had the opportunity to speak to a young woman who eagerly asked about comics when she saw me reading one. She explained she did not regularly follow them because the patrons and employees of her local store had criticized her to the point that she did not feel she was welcome. I wish I could say her experience was an isolated one, but I know it isn't. Many comic stores often have a suspicious stigma toward curious new customers. With comics becoming more and more "mainstream," simply saying you like Marvel may be cause for sneers, and confessing an affection for Hawkeye may you get you laughed at. The condescending comic nerd is a cruel stereotype, but it is an effective one for shutting down intrigue in newcomers to the medium.
Sadly, the simple fact is that current comic sales are not enough to warrant such frivolous selectivity in terms of fan base. A graph of yearly comic sales over time is soul crushing. The ship is sailing, but these are turbulent waters. Better sales would make for less dependency on gimmicks, crossovers, and events. It behooves us all to have more fans, but the barrier to entry, which is already high enough from decades of canon, is made even steeper still by an unwelcoming environment. This is before you even consider the lack of store availability. Many who learn I love comics are shocked to learn that monthly comics are still in publication. It's a dangerous time, but there's hope. I believe comics are a medium with a power like no other. These aren't just stories, they are the adventures of icons. I believe that young girl was just the sort of person who needed comics, and her store failed her.
I know she was failed because I wasn't. My local store is wonderful, and after seeing so many others I understand how lucky I am. When I first started reading, employees and other customers were wonderful teachers. I found a place where I could learn about this amazing and ever-expanding narrative world. Although such information is readily available on Wikipedia, an Internet search cannot compare with having all those stories at your fingertips and a guide to walk you through it all. I believe in this strength lies the true power of comics. These are not just stories, they are modern epics. The heroes of the big two have come to stand for something, and their decades of trial and tribulation make for a narrative experience unlike any other. Comic stores play an important role in that. I'd argue that a TV show wouldn't be the same if you simply had a box set released once a year. Comics, which are more intricate and ever expanding, similarly rely on a constant outflow of story to fully embrace their potential.
This is where the latter component comes into play. Can digital outlets remedy the situation/replace comic stores?
It would be easy to argue that services like Comixology and Amazon could make a comic store irrelevant. You could simply get your comics digitally or wait for trade paperbacks and never have to play the roulette game of entering a comic shop. If years of lending books to new readers have taught me one thing, it's that the landscape of comics is harder to navigate than a game of Jumanji. (Come on five or eight!) I pity the fool who is an X-Men fan hoping to jump into the comics blindly, with no prior comic reading experience. That said, I think vertical integration can be dangerous. It only took three issues to change Nick Fury into Mace Windu. While I think it is good, if not imperative, to capitalize on the success and subsequent new interest created by the recent wave of comic films, I do not think this should come at the cost of continuity, especially when comics can still be accessible given the help of a top-notch distributor. Furthermore, if comics are to be the modern mythos, then we should continue trading stories in the way that has worked for thousands of years, between excited parties who can revel together in the sensation of an exciting yarn.
Getting into comics can be difficult. A good store may be hard to find. Although the stories are good, it takes some time to get up to speed. There's interest, but there's also work to be done to bring others along for the ride. Maybe this means it would be best to have a place where you can go to learn about them and enjoy them with like-minded individuals. Wait a minute, we already do. Now we have to keep them that way.