My understanding from other posts here, is that Bendix had a nearly insurmountable arsenal of patents on washer/dryer combo designs, operation, and mechanisms.
So if any other company wanted to make one, they either had to pay numerous licensing fees to Bendix, produce a less-capable / less-refined machine, or they had to come up with very complex designs of their own to address or solve the necessary issues without infringing on the Bendix patents.