It may sound like a moot point, but marketing is what's getting people to buy things. You don't see Pioneer home audio in ads on the internet or being pushed in retail stores. I just did an 'zon search for both Onkyo and Pioneer. Onkyo has home theater in a box package deals with a receiver or without. Pioneer really doesn't. They have a few Andrew Jones HT speaker set, but none with a receiver. People are mitigating their audio gear. Why have a dedicated computer when you can have a phone/tablet and even game system/HDTV that lets you connect to the internet? Same with audio. Dedicated separate receivers/speakers are being exchanged for HTiB with receiver or even more simplified "soundbars".
I've seen a few homes with "surround sound", but it's the tiny speakers that don't take up a lot of room. That means people who buy an Samsung or LG HDTV will go buy a "matching" Samsung or LG HTiB or soundbar because they are now brand loyal. Samsung/LG systems are cheaper than Onkyo or Polk HTiB. If people are going to spend more than a few hundred, they'll probably go with BOSE because they "initially" sound great, so they think the price is going to get them much better sound. Plus, you have to admit, Bose do look more aesthetically appealing so it doubles as "good sound" and good decor. Onkyo also has dedicated little iPhone/pod desk players that Pioneer doesn't. Pioneer really isn't making a lot of products that will be "welcomed" to the average buyer and only in the car department like head consoles and car speakers are they even on display to buy.
I hope Onkyo starts using some of Pio's home audio to fix their new lineup of receivers. I have the Onkyo TX-NR807 and lucky enough my HDMI board isn't problematic, but does run super hot (fixed it with an external 240mm fan blowing down). It has a large brushed metal face with heavy door that hides all the extra buttons and a giant metal knob. The new series, I saw at a store and the knob is smaller, and it has a LOT of wiggle. Mine barely moves. It feels sturdy. I don't like the flat face, and it just doesn't feel solid. They really did take a dive with the new receivers. Hopefully unifying Pio will change that.