Nexus devices are NOT "developer-only" devices.
People have been saying this a lot lately when talking about sales figures (however you perceive them) and marketability.
There was a time when Google pushed the Nexus One to developers, but that was quite a while ago. Developer-only devices wouldn't get frequently-airing TV commercials showing children playing with them, and banners hanging in local malls. Until you see ads saying "UNLOCKABLE BOOTLOADER" and "HUGE CUSTOM ROM SUPPORT", they're obviously not being pushed to the dev community.
Nexus devices are Google's cautiously-optimistic way of getting consumers to use their services, including the Play Store. They just happen to be dev-friendly, too.