The launcher manipulates gravity? Wow, I wasn't aware they could code that well.
Most people aren't having issues like this. And besides, on your laptop... the launcher shuts down after it opens Minecraft. The launcher isn't what's causing your lag.
You are not a customer. You are not buying a product. They are providing this free of charge. That's like complaining that the free soup you got at the soup kitchen isn't good enough for you.
Of course it isn't fully functional. Did you look at the version number? 0.5.3.6 It's a work in progress. And also, on your last part? Where you say you bet the average computer user can use it with no problems. In the last paragraph, you just said it was too difficult for the average user to use. Make up your mind.
Good for you.