Definitely not about smart consumerism or spending wisely here.
Back when the Denon AVP-A1HDCI came out, I was going to also buy the matching 150W x 10Ch amp. But what stopped me was the WEIGHT of that thing. If it had been like the weight of the Marantz AMP-10, I would have bought it for sure.
So extremely enthusiastic hobbyists who would buy the AV-10 would be tempted to get the matching AMP-10 because it's just cool.
Like when I got my Yamaha CX-A5100 AVP, I also got the matching MX-A5000 AMP just it's just cool.