Provisional matches and placement

So whats up with provisionals. This is my first real season of LoL. I just barely managed to start playing at the end of last season, getting placed in B1 after going 2-8 in provisional matches because i was awful and only knew how to play support but decided to jump into ranked anyhow. Now I've found some carries i like and am playing much better. I was exited that last season ended and new provisional started so that maybe i could get a look at how I've improved at the game. After playing nasus for all of my placement games i ended up going 8-2 in my new series but was crushed when i was awarded B2 lower than my suck streak from before where i had no concept of ranked. I thought the whole point of your provisional series was to allow the system to place you (albeit a bit randomly) based on a few games and then either beat you down or allow you to climb up if you where not in the right skill level not carry over your ranking from last season and place you even lower than before despite winning more than losing. Why bother having a provisional series to gauge your skill level if your always going to be placed at the same skill level you left from or lower. Why have a provisional series for someone with high elo/mmr when all you can really do is lose. Could someone please explain the logic here? Do they want people to smurf because they think having more LoL account will make them look good for advertising or something? I'm at a loss