I know that Safari does not support everything say Chrome does, but if you do not need those features, what does it matter? An example: I use Safari without having flash installed. I rarely need flash. If I do need it, I would rather open Chrome and close it when I am done with the flash thing and go back to Safari. Why? Why not use Chrome all the time since it supports (almost) everything Safari does and more? Well, because in my opinion, for what I use a browser for 99% of the time, Safari works better. I think it looks, performs, functions and feels better overall. So I would rather use Safari and switch to Chrome when I need something Safari does not do, or Chrome does better, even though on the paper spec, Chrome is the better browser.
It is the same reason I use an iPhone even though Android "has the same and more features".