Oh right a podcast or two talk negatively about Streetpass, perfect reasoning to suggest that "barely anyone uses it". People had mobile phones a few years ago too you know. Difference is there weren't 50 millions 3DS systems out there being played on the go. You say you don't get Streetpass "other than in huge cities, and even then barely", people on this very thread are saying they get 10 easily in one trip out. I certainly do, I take my 3DS about in London but also on the train to other places in the UK and I always get lots of hits. Don't speak unless you know what you're talking about.
Why is it "bizarre" to call puzzle pieces, extra in-game perks because of Streetpass hits a reward? That's what they are. Likewise play coins.
Again, it isn't "nobody wants to do it", it's not a "slim chance", and there's no "may" get a reward, you will get a reward.
FFS. For the millionth time, Streetpass is there as an incentive to take your 3DS out with you. Why would Nintendo care if you bring your phone out with you, but leave your 3DS tucked up at home? They want you to bring it out, show it off, spread word of mouth etc. Why would Nintendo give Streetpass hits to someone who takes their mobile phone out with them, as every single person in this country does. Why not just give them free points every day? You might as well just ditch the service.