Because 802.11 is HARD. The number of companies that build full-featured and modern chips is small, and the barriers to entry are high. For example, if you wan

Because 802.11 is HARD. The number of companies that build full-featured and modern chips is small, and the barriers to entry are high. For example, if you want a full-featured chip for building an AP, there's maybe three companies capable of giving you one - Atheros, BCM, and Marvell. And that last only sells to Cisco. So you're stuck between two companies with drivers that are awful in slightly different ways, and only a year into working with one or the other do you discover the firmware bugs. If you want previous-generation-equivalent chips there are more suppliers available, and some of them probably have decent drivers, but they're uncommon in developed-country markets.