Let me count the ways.....
Actually there are only two. No purling and minimal finishing. It is really that simple.
Because I knit Continental style, knitting is a breeze - fast and easy - but purling is more complicated. So, circular knitting = no purling back across an interminable row.
Just because I don't like to work thousands of purl stitches across a row, doesn't mean that I don't use purl stitches. Some of my favorite stitch patterns are combinations of knit and purl. That's right - textured and ribbed patterns knit in the round. As long as the pattern has a nice rhythm and is easily memorized, it is much more enjoyable than plain knitting. Lace patterns fall into that group as well.
As for the other reason for my love, I have been known to go to great lengths in the planning stages of a design to ensure as little sewing up as possible. Mostly because I like to be done when I'm done and also because an item finished with that kind of thought seems more of a piece - more whole, I guess.