I think I lost every one of my placement matches and landed in Platinum. It's certainly more about how you play than your win ratio, but I guess 'tons of wins' is a term for 'tons of practise'.You don't need a "ton of wins". You just need to be good enough. I went 4 and 1 during my placement matches and got Platinum.
That being said, if you're pretty new to the game, you won't make Gold. Gold is generally players that have a decent grasp on the macro side of the game. If you can keep making workers and keep your money low always, you'll probably make Gold. If you don't make Gold right away through placement, it might take quite a few matches to get bumped up from Silver.