Snapdragon laptops have been available for a few weeks already. Although laptops cost more than this dev kit they're also more usable as a daily driver. If Qualcomm wants real adoption they'd send them out for free, not require devs to pay.
Dev shops would rather not have piles of laptops with batteries to maintain sitting in their racks/shelves for build and remote testing.
For individual devs laptops are fine, usually, but there's also no solid "reference" platform, since all the laptops are targeting different consumer lines.
That's a bit beside the point though, the Dev kits should've come out months before the consumer products were launched... and failing that at the same time.
Qualcomm and Arrow said the units would ship "tomorrow" in July... and it took over a month (after accepting many orders) before they even updated the stock to a more realistic timeframe, late September.