The Name is Bond: These lenses are excellent even if they aren't exceptional. The conclusion is bizarre, even more so since they are so so cheap and yet not cheapo plastic fantastics.
This picture needs adjusting.
I think the conclusion may be a bit biased because there are so very many options in the 15-20mm range in m4/3. I chose to go with an Oly 17mm 2.8 instead of the Sigma 19mm. The price isn't much different, and at the time I bought the older Oly lens worked out cheaper. And it's not like most of the kit zooms are bad...
The around normal 25-30mm range is less crowded, so the 30mm stands out more. The other options are all a lot more expensive for a pretty small amount of low light performance.
And for reasons that escape me, it seems like people tend to buy primes for wide angle and normal use more than they do for tele. I've got a 50mm prime for my m4/3 and it tends to spend a lot of time glued to my camera. Very flexible lens. So it might be people tend to discount how useful a longer prime can be.