Because Lizards with metamagic/anti-magic are awesome. Because I liked the SL banner most when I first started playing. Because Basilisk Templar, Skywing Beacon, Rumbler and Transmission Relay are fun. Because I enjoy beaters. Conceptually this faction is awesome. Regenerating lizards that mutate according to their needs or use anti-magic tailored to their opponent. Too bad the actual faction isn't that awesome.
I started just after the Shattered Peaks expansion. Since I bought only SP expansion packs, I ended up with a lot of SP runes. My first 10/10 deck was designed around skeezick trapper and moga trigger. That's when I learned that I liked SL better than SP, and switched my primary faction over. I haven't looked back since. I still play other factions, but SL is by far my primary.
I like anything that has to do with the desert and wastelands... Lizard men, mutant skeezicks, sandy critters, sand storms... Need more desert sauropods.
Dragons are the most bad ass thing in fantasy, EVER! So why not play the factions that has dragon gods and dragon people. Mutants are pretty bad ass too.
Also we get to be split with SP and that gives us the best thing in the world, Kanen! Who wouldn't want to play werewolves.
Dragons and dragon gods. Mutation, fire and acid, violent lizard men, the general sandy wasteland theme, giant sand beetles. Myx were the initial reason i ventured into SL, giant acid spewing sand beetles are pretty cool. Sundered Lands has a good theme.
Having your champions survive is helpful for planning things. Also Draconic Benediction was great when there were fewer runes. Once sand runes came out, I kept playing
I originally set out to play Dwarves when I started buying packs with gold, but it so happened that I was getting a lot of Draksar champs (and some Skeezick on the side) so I changed my mind. I also thought that the idea of having a race of strong beaters who had regeneration and decent damage due to Violence, on top of taking reduced damage from attacks because of their faction bonus, was pretty OP. Well, I'm not so sure about that now...
Heres a good tip for Vex, she cant be blinked on terrain different to normal such as rocks or chasms.