Personally I'm not convinced that much good comes from this "race to the bottom of the market" in terms of ultra-cheap hardware with every possible corner cut off it.
They've used a CP2102 as the USB virtual UART chipset. How fast is this virtual UART? Probably significantly slower than the speeds you will expect with an ATmega8U2-based system. And you'll need the drivers for that chipset installed on your PC, too. Are working drivers available to suit your operating system? Maybe.
You need a custom-patched version of the Arduino IDE to add support for this hardware target. You can't just use it with a stock Arduino IDE that you've downloaded and installed.
And if the firmware on the microcontroller is somehow corrupted or replaced, are the appropriate files, toolchain and documentation available to allow you to successfully re-flash it? It's not clear that this is available. And if not, what? You throw the hardware in the bin?
In some of the photos it looks like they're not even populating a crystal on the board. Are they using an internal RC oscillator? Then for best results the user should understand that that's the case, and that you can't have really accurate timing.
And they've changed the voltage regulators... how well documented is that? Are the specs really trustworthy?
They specify the maximum allowable input voltage is 24V... and you can clearly see there are a couple of 25V rated tantalum caps in the power supply input part of the board. Thick purple tantalum smoke here we come! Even if you use the board within a reasonable voltage limit of say 15V, what is the realistic current output available from the 5V and 3.3V pins to power external loads?
And even if the microcontroller really was "close enough" to an ATmega88, you have to recognize the memory limitations of an ATmega88 compared to an ATmega328 you might be used to. Even with support for that chip added to the Arduino IDE, it is likely that many existing Arduino programs that are tested and working on a real Arduino Uno or equivalent will not work.
Many of today's Arduino programs/examples out there in the community will fail to work on an Arduino bootloader equipped ATmega168 with 16k of Flash, and going to an ATmega88 is half as much again.
And when it all goes pear shaped, somebody who doesn't really know what they're buying goes and posts on the Arduino forums etc and says I bought an "Arduino" and it doesn't work! And the Arduino team in Italy, understandably, gets pissed off.
If the third-party company released Arduino-compatible products clearly labelled with their own brand, under their own name, with their own website where you could go to for support questions for that company's products, and it was clear that this is not "from Arduino", it's released and supported and manufactured by a third party company even though it is Arduino-compatible. A lot of the cheap Chinese hardware makers really fail to do this at all and I think this is what pisses off the Arduino team in Italy, whereas Sparkfun or Freetronics, for example, are responsible in this regard.
Basically, lots of little subtle complexities make it harder to use, especially for less experienced users who are just starting out learning to work with Arduino. For users who are just starting out learning to work with Arduino, I would recommend buying a known reliable, well supported hardware platform, from the official Italian Arduino team or from Freetronics for example.
The people that this hurts the most are newbie Arduino beginners, not experienced electronics enthusiasts who understand what they are and are not buying.
And then they go and complain to the Arduino forums or something that "their Arduino does't work!"
And then what? The Arduino team gets pissed off about "counterfeiting", the Arduino team is more likely, perhaps, to move away from openness in the future and start keeping designs closed, and people think that Open Source Hardware is a failure from a business perspective and the misconception persists that you can't build a viable business around OSHW because China rips it off.
And the misconception persists that everything China makes is shit, and the misconception persists that as an engineer you can't touch China at all and you must not have them involved with your manufacturing at all because they are nothing but poor quality, IP theft and generally engineering poison. Are these misconceptions good for Chinese business? Wouldn't it be in their best interests to address them?