i think there are two reasons there are differences in people's lives pre Oceanic 815:
1) Everybody is focused on the fact that the biggest change in "the past" is that there is no hatch and thus no crash. But there was a lot of meddling with the past. Heck, they exploded a freaking nuclear bomb in the past and shot young Ben etc etc. All of these events affected the future/present as we know it.
2) We know that Jacob interferes with peoples lives to get them to the island. WIth no hatch, he probably interfered differently. I suspect the flash sideways people are on a path to the island right now (thanks to Jacob's tampering with their lives). It just won't be Oceanic 815 that gets them there.
On a tangent, a key motif of the show is free will versus destiny. We are seeing it more and more as an important part of the narrative rather than just a motif. Quick example is Dogen saying Sayid had to freely decide to take the pill. Also consider how Ben then Jacob have consistently manipulated people to "choose" to do exactly what Ben and/or Jacob want.
Now, remind me, what was Sawyer's "job" before the island?? Mmmm hmmm.