As a new MO player who is trying to learn the game by playing as Scorpion Cell, I LOVE this faction. However, I can understand why some new players are turned off from playing SC: this faction relies very, very much on fast economy development in the early game. It took me a few weeks and a lot of defeats to figure out the fastest way to get a few miners out.
If you're not fast like a Formula 1 pit crew in the early game, you're giving away SC's biggest advantage: the ability to roll in behind your opponent's base with a few basic tanks before he/she has any serious forces or defenses out. Then, your tanks are fast enough to pull out when the going gets tough and losing a straggler won't cost you much anyway.
If you're a new player who hasn't yet become razor sharp with your early buildings routine, it can be frustrating to see this window but always have it close JUST before you're able to take advantage of it. However, once you've mastered it it's loads of fun because almost nobody expects to be on the defensive that early.
Playing SC in late game is a little unorthodox but it's not impossible. SC (and Epsilon in general) relies heavily on the "tricks" available to them - weaver trap, fake structures, using plague splatters to clear infantry rather than for direct damage, etc. Malver exemplifies SC's strategy by being very vulnerable on his own but very powerful when the opponent is distracted from him. (Even Rhino tanks and Tesla Cruisers are not so hard to kill when they're debuffed!) Speeder trikes might be the most important unit SC has.
A lot of new players like to win by building up a bunch of direct assault units and steamrolling their enemy, but this is hard or impossible to do with SC. I think that's why a lot of people gravitate towards Russia / China instead.