I'd not call it a letdown at this point and more the industry standard norm of scalpers able to outwit multibillion $ corporations.
Also, if something sells out within 30 min, that's no longer a lack of supply issue but more they didn't even bother to you know like do some accurate sales projection analysis or something.
How many scalpers can there be? Couple of hundred on eBay? A thousand listings?
If the Steam Controller launch repeats, the upcoming SteamOS console will be in short supply for months. Valve has told new buyers not to expect the accessory to ship before 2027. High memory prices and a component shortage have already delayed the Steam Machine release date.