Before "genius bars" and FruitStores, Apple users provided a huge amount of self-support on Usenet. While long having appeal in the creative community, our uses were statistically pretty small and getting help meant software authors and newsgroups and even BBS (showing my age here).
Apple has done the math and figured out how many buyers who require no live support it takes to provide that support to those who do need it. Kind of like insurance, the folks that don't need it today subsidize those who do. Your turn might be next. And getting you into the store gives them the opportunity to up sell demonstrate new products and accessories. It's to Apple's advantage even if your visit isn't initially for shopping.
I don't think your $300 Dell/Walmart analogy is valid, though. You bought a discount product at a discount retailer, fully aware of the potential support limitations and likely build quality. I think it would be unrealistic to expect Apple-level support at 30% of the price. Apple can't do that, either, and charges a premium price to provide support (among other things). The Fruit product is a value if you need in person support, especially if the product is used in your trade or business. A big slice of their market, though, will never *require* a genius and online/phone support works, if needed at all.
Finally, your comment about Uli having an in-store "store" at Banjo Depot. The economies of scale don't work. Apple sells a premium product and sells millions of them. How many Apple Stores are there in the US? I know we don't have one here in Wichita (MSA of ~600,000 pop) but we have a Banjo Depot, and BD is in smaller markets than ours, too. Not sure how a value-product manufacturer could be expected to provide in person support for the *dozens* of X32 or *hundreds* of amps, other mixers, etc in this market. They aren't selling iphones and pads...
I think what is potentially important is that this is, I suspect, the opening salvo of integration between brands and product lines. Much like Harman is still doing, Music Group appears to be charging into at full speed. At this scale the only players are Harman, Yamaha and Music Group. Being able to affect Yammy and Sid's Kids IS game changing from a business standpoint, the hoopla over the x32 not withstanding.