The reddit survey was advertised on reddit, the D2R forum here, d2jsp, and Rhykker’s youtube channel. It had >4,000 respondents. Certainly, this is not as important as Blizzard survey where they asked if players were interested in personal loot instead of FFA loot at D2R launch.
I suspect that Blizzard may (or may not) revisit the issue after the multiplayer alpha/beta. I think it will come as a bit of a shock to many game testers that the game does not have instanced loot. I know what to expect since I played D2 at launch.