You are arguing against your own poll results using terms like 'I believe'. The only evidence you have are the poll numbers. That is what you must base your conclusion on. Anything else shows a gross misunderstanding of the simplest of statistical mechanisms.
As to the results, other than your own bias and given the tiny sample size, there is nothing at all precluding the outcome that S1 really is that much more popular with ex Sonar users than anything else on offer. Interesting, but not that surprising.
It was a fun idea. I wouldn't overthink or second guess the results. You have to ask yourself, is there really anyone out there with so little else in their life they would take the time and effort to skew the results of an insignificant poll in a forum thread?