In my experience with Apple stores, they work great when customers act the way Apple thinks they will (or should) act and not so great when they don't. Ironic, considering a company that at least used to champion giving users choices and encouraging to not be a part of the crowd, though it's been clear that company died a while back.
I don't participate in the launch frenzies to know the details, but from accounts, it should like those principles still apply. Do it our way, or no way at all. Deviate, fall into the cracks, and good luck escaping. You'll be a mummy before anyone finds you.
During normal times, the secret to Apple Store Happiness is to find the Person Who Holds The iPad. They act as a dispatcher, as well as a traffic cop of sorts, and have the magical power to put you into the invisible queue which determines who gets helped, and in what order. In most stores, it would be like getting into a line, or taking a ticket from the dispenser, but at least those are plainly obvious.
That's essential when a store is busy, the staff is fully occupied, and doesn't pay attention to anyone except those to whom they've been assigned by the iPad Person. If you happen to get the attention of someone they'll still tell you they can't help, and hopefully, you get successfully passed off and put into the invisible queue somehow.
But I've also found it may be necessary when a store is almost completely empty, and the staff nonchalantly acts busy with other things and ignores customers, almost all of whom were huddled around the same table with only a single poor staff member trying to help. I actually had to track down the iPad Person, who seemed a bit miffed I bothered them, and tell them that we needed help before they dispatched reinforcements. If I hadn't needed to make a purchase that day, I would have left due to the p!ss poor attitude and service. In an empty store.
During most times, when a store has traffic but isn't slammed, and is well staffed, it then depends on how helpful those working are. If they're attentive, proactive, and offer assistance, it can be a quick and pleasant transaction. If, for whatever reason, the staff isn't attentive, would rather hang out with each other than attend to customers (which I've also experienced), then that requires needling the iPad Person and having them rouse one of the staff into helping.
It wouldn't be so bad if there were clear and obvious indications as to how Apple expects the store traffic to flow, like in most retailers. But there aren't, so that places an even greater onus on the staff to bridge that gap, and sometimes, that fails, making the experience worse.
Irony strikes again when Apple takes measures to clearly delineate the process, better manage the traffic flow, and it still results in a poor experience, as it did for the OP.
In the early days of the Apple stores, the Genius Bar was a new and genuinely helpful resource, and the staff was comprised of Apple enthusiasts who probably migrated from other Apple specialist outlets.
Things have obviously changed, some of it unavoidably given the success Apple has enjoyed, but now it's closer to common retail. Above average, but still retail, with unevenness, and much of the depth and experience gone.