Simpleplanes has a steep learning curve. It's easy to play, but very hard to be good at. Try spending a few days, then a few weeks, and then a month or so on a plane. Go for details, appearance. That's what makes a good plane. Patience.

@Treadmill103 @Jengstrom Thanks for your help

From looking at your profile, you seem to go for high output over high quality. If I try and build a plane that will get more upvotes, I spend at least a week on it, and have a lot of detail. Upload time can also be a factor. Watch for website activity, and upload when you think there may be a lot of people active. On my old account, it took me almost a year and a half to get to silver, so calm down. You'll be recognized in time.