Originally Posted by MKahrl

The reason the threadless stem was introduced was to benefit the bike manufacturer. Customers no longer had any choice once the switch was made. They've been around long enough that most riders don't even remember that there was a time when you could adjust your handlebar height to suit your mood or conditions for that day.

It's not a fad.

Sky Yaeger, Bianchi VP, when asked if quill stems were totally dead in the dealer market replied, "Dead and Buried. On a factory and supplier level threadless is much better, although the customer doesn't give a whit about how it is easier to manage inventory, cut down the number of separate inventory items, and related bike-assembly issues. The only downside is the lack of minute adjustability. But now we have 2 and 4-bolt stems to swap out handlebars easily and that is key at the dealer level. Everyone in the supply chain can manage inventory better, because we need to manufacture, sell, and inventory only one fork steerer length."