Hi Worf,
1. "Reference" really doesn't mean anything anymore; it's a marketing ploy. Originally it derived from recording studio applications, both for speakers and electronics, where "reference" suggested impeccable specifications and very linear frequency response. Tests have later shown that in terms of some classic studio "reference" speakers, they were anything but linear, however they were indestructible and could handle large amounts of input power and produce high SPL's.
2. For traditional Class A/B solid-state amplifiers, I would generally agree that simple, easy-to-cool two-channel amps or monoblocks are better than 5 or 7-channel power amps on one chassis. One exception is new technology, like Axiom's A1400-8 digital amplifier, which effectively puts 8 channels on a single chassis that barely runs warm. But that's because it's a digital amp, not analog, so it's very efficient, up to 93% at full output versus 50 to 60% for a Class A/B analog amp.
3. One of the reasons that pro amps don't find a market with home theater consumers is that little or no attention is paid to design cosmetics. They're just black boxes, often rack-mount, and, as you've noted, equipped with XLR or 1/4-inch phone connectors, which scares off a lot of lay folks familiar with only the lowly RCA connectors.
But there are certainly virtues in using in pro amps. Typically they're very rugged, with big power supplies and solid output power into low impedances with no persnickety protection circuitry that shuts down the amp when it smells a 4-ohm load.
Regards,
