As stuff is stored into, left, and eventually pulled out of RAM, some corruption naturally occurs (theories vary, but the one with the most weight right now is EMI from the computer itself). ECC is a feature of RAM and motherboards that allows detection and correction of this corruption.
The corruption is usually pretty minor (ECC can usually detect and fix 1-2 bits per 64 bit "word" - and that's waaaaay beyond the typical error rates), but increases in frequency with the density of the RAM. Your average workstation/PC will never notice it. On a server where you're running high density RAM 24/7 in a high-demand environment serving critical services, you take every step you possibly can to prevent stuff from breaking.
Also note that ECC RAM must be supported by your motherboard, and the average workstation/PC does not support it.
ECC RAM is more expensive than non-ECC, is much more sensitive to clock speeds, and can incur a small (1-2%) performance hit. If it helps, an analogy that works is RAM to RAID controllers. On your PC, that hardware-assisted software RAID built into your chipset is great protection against single disk failures. On a server, that would never be enough. You need high-end, battery-backed fully hardware RAID with onboard RAM to ensure that you don't lose data due to a power outage, disk failure, or whatever.
So no, you don't really need ECC RAM in your workstation. The benefit simply will not justify the price.
ECC RAM can recover from small errors in bits, by utilizing parity bits. Since servers are a shared resource where up-time and reliability are important, ECC RAM is generally used with only a modest difference in price. ECC RAM is also used in CAD/CAM workstations were small bit errors could cause calculation mistakes which become more significant problems when a design goes to manufacturing.
Best Answer
After researching this for a while, I can't come to any concrete conclusions, but I can make some strong inferences.
The techreport article you link to seems to be the only place reporting the lack of ECC ram. Everything else that I can find that references it, stems back to that article. But that article is unsourced and as far as I can tell, unverified.
I would believe ARK over an article of unknown journalistic quality.
All that said and done, ask yourself "Do I really need ECC for a home server?" - take for example this 2015 article from our co-founder and former overlord. I don't always agree with all of the server/hardware decisions Jeff has made/posted in the past, but I can't deny that in this case he seems to have done some pretty thorough homework.