It's both easier and simpler

Exactly. Commercial licensing places the compliance burden on the legal and accounting departments. Copyleft licensing places most of the burden on the engineers. And since engineering is always, always, always the bottleneck when getting a consumer electronics product out the door, it greatly amplifies the cost of compliance.

Also, GPL violations are ubiquitous in the CE world and almost everyone gets away with it. It's just not something most small and mid-sized OEMs are concerned with in the least.