If you mean 35mm shooters as in movies, I don't think there really ever were too may of those (I'm ordering it for use as a still film.) I think a cinematographer or two convinced Kodak to make them some Ektachrome stock in 35mm with B&H perfs and Kodak went ahead and made a big batch of it to supply them and had a bunch left over. I never really saw much of an effort on their parts to market it, it just kind of sat in their catalog. But the side effect of that, which was a *huge* win for the 8mm/Super 8 shooters, was that it finally once again made available a film they could shoot, get cheaply processed (even process themselves), and project. No need for a processing house that could make prints from negatives, since those have all but disappeared. And Kodak, bless their hearts, did make some actual effort to support that and market it.
The problem, ultimately, is that no matter how rabidly that community liked and consumed the film, it just wasn't enough to get Kodak to make any more. Heck, Kodak stopped making reversal film for 35mm still cameras, and you know that market was a gazillion times bigger than the market for tiny film based movie cameras.
I've got a freezer full of bulk rolls of Fuji 35mm slide film, but I don't see where those are available any more, at least in the US. I think E6 is winding down, unfortunately :-(