I don't think a lot of tiers are bad if they're smartly done and re-visits of previous tiers that sold out. For instance, a $20 tier digital download version of the game, limited to 1k, sold out. A $25 tier that's a digital download version of the game, limited to 2k, sold out. A $30 digital download of the game, unlimited. Then, a $50 digital download with exclusive, not open, beta access, limted to 1k, sold out. A $55 digital download with beta, limited and sold out. A $60 digital download with beta, unlimited. Etc.
This is why things need to be staggered some. Beta needs to be high enough there's room for non-beta to be enticing. Alpha high enough there's room for beta to be enticing, etc.
They really should lower the cap on many of the tiers to let them sell out, then just restructure the whole thing. They may get some backlash from people who see alpha slots gone at half the price of the new tier, but it can at least be explained they wanted to reward early supporters (instead of just ignorance), and then alpha can be put at a higher tier where it belonged.
Pull the tiers with zero backers. Cap the tiers that are fubar. Get proper tiers in. Deal with the tears of people who aren't getting the same value as people who pledge early. It will be a representative microcosm of the game's philosophy, so a good thing!