As another person who plays by having the app open when I would be walking somewhere anyway, the loss of the tracker means absolutely nothing to me.
Safety is a moot point; people should not be walking around paying no attention to their surroundings whatever they're doing; that is the onus of the user, not Niantic.
Like some others, I find the argument that using a tracker enables a better community spirit rather puzzling. What's so social about checking a tracker, hopping in a car and driving to a spawn? Sure, you can do it in a group, sprinting haphazardly to try and catch something rare, but the enjoyment there comes from sharing an experience with other people, not specifically from the tracker. Yesterday a housemate and I went on a long walk, taking detours here and there from our normal route into town, just following the paths and waiting for vibrates, and we had a blast. We would exclaim to each other about the pokemon we just found, calling each other over, and when a pikachu appeared out of nowhere, well, we were both over the moon.
The existence of the trackers never bothered me, but there's a degree of entitlement in people getting so upset at the loss of something that was, when all was said and done, cheating. I expect that a tracking feature will soon be reintroduced into the game, which should alleviate some of the stress, although I personally won't get much use out of it.
Actually, this is not technically true. My American friends reported their footprints being fixed (displaying one, two, and three) while up here in the North mine was still threes-only. We are not playing QUITE the same game. Honestly I had never heard of nests before today, they simply aren't a thing I've been exposed to yet.
The three-step bug isn't fixed for anyone, unless it happened in the last few hours; although it was recently removed altogether in the form of the steps being taken away completely. I strongly suspect that nests are indeed found everywhere. Certainly they're here in the UK, and I couldn't find any sources suggesting they're exclusive to certain countries. They're rare; you not having seen them is not proof that they don't exist in Canada.
If you truly believe that you're not on the same version of the game as some other folks, you can always check for updates for the app? Updates get pushed everywhere simultaneously, so if you're behind, you may just need to install the latest patch.