Making a really good sounding amplifier is actually not that difficult for a good engineer as the best designed have been commonly known for decades and components are better and cheaper than every before.
Why we don't see tons of great amps out there is that there are several aspects to manufacturing electronics which have less to do with performance than with good business practices. For instance, ensuring any design can be manufactured consistently - with similar performance and reliability - for the sales life of the product is a complex and time consuming task. You have to create a good supply chain which makes certain all the parts are available for 3 to 5 years (or longer) that you manufacture the product. You have to also find a good manufacturer which can do good work consistently at the right price, etc. All of these things have to be balanced with the price you want to sell the amp for. Then there's all the aspects of the need to have repair parts in stock - too much and you are wasting money, too little and customers will get angry with you.
It isn't easy to be a good manufacturer. This is why you find what appears to be incredible deals on amazing gear on the web and wonder why those companies don't rule the industry. Well, they are making decisions which are not the same as someone like Parasound. Some will design and produce a fixed production run of an amp - meaning, they have a Chinese manufacturer make 10,000 units and put them in a warehouse - then break down the manufacturing floor so it can used for something else. Once the supply is sold out, that's it. If it is a wildly successful amp, customers get frustrated because they cannot buy them once they are out of stock. And, to start over a new manufacturing process for an amp isn't easy, so it makes more sense to design a new amp and make it. Then you run into quality and consistency issues. 80% of the amps can work perfectly for years, but if 20% fail too early or don't perform as expected, then you lose customers and have reputation issues.
While I have no definitively knowledge of Emotiva, I get the impression they are in the latter category of gear makers. Behringer is different. They are big enough they can continue manufacturing their stuff until obsolete or there is no demand. They also borrow manufacturing tricks from other companies who invent new things. They get more trash from being copycats than from being crappy gear.
