As a retailer, an online one at that, we'd love to carry more boutique cigars but honestly they don't make it easy for us to bring them in. IF they let us bring them in at all, we don't get any discounts on their product, have to adhere to MAP pricing, are often required to bring in the entire line and not just what brands or sizes we know we're going to sell, we can't discount the sizes or lines that don't sell or we risk losing the right to sell any of the products or being stuck with product we can't move, and there's no easy way to buy a whole bunch of boutiques at one fell swoop as we have to deal with each company individually and not through a distributor in most cases, which for us is a major pain in the ass.
And honestly, for the boutique brands we do carry the 80/20 rule the article talks about is really more like a 90/10 or even possibly a 95/5. You wouldn't believe how much ACID, Padron, Perdomo, Oliva, My Father and other big brand product we move.
We are however actively looking to expand our boutique offerings, it's just so hard to know who to take a chance on and who to pass on.