I read this too and I think its an interesting survey.
I often wonder about the methods used to conduct these types of things.
It would seem to me if it is done by asking owners to compare their product to a theoretical "best" then I have a bit of an issue with it, particularly if the survery participants are drawn from owners of all Suzuki and BMW models.
Imagine you survey Suzuki owners, everything from the GS500 to Hayabusa. You get an extremely wide variety of owners, everything from the very experienced to those on their very first bike. Does a person on their first bike have quite as critical an eye as a person who has been riding 5, 10 or 20 years? Possibly, possibly not.
On the whole I would say BMW buyers tend to not be first time buyers and may rate their bikes more critically.
I believe this line of thinking would also hold true even if it were limited to the V-Strom lines and GS. When I had a 650 Strom I noticed that many of the owners were first time buyers and many others were hesitant to criticize anything about the bikes because " they're a good value for the money." (which they are).
I have no idea if owner experience is a factor in these surveys or even a valid isue. I would think so or at least something that has to be corrected for.
Having owned a R1150GS, 650 Strom and my current Tiger I can say all are good machines. IMHO, the Suzuki has the lowest quality fit and finish, lacked in detailing, but was quite reliable. I felt that BMW had the best fit and finish and was certainly the most fully refined and developed package although my particular bike gave some trouble (much of it related to dealer issues IMO). The Tiger is somewhere in the middle on finish and has so far been stone reliable and the most fun to ride of any of them (subjective of course). Its fairly well developed as a package but shows a lack of detailing (for example, why three locks for each saddlebag, not keyed to the ignition key)