It's very simple. If a company manufactures and sells three times as many boats as any other, it stands to reason that there would be three times more of them on the "used" market than any other.
BTW, Wal-Mart doesn't sell cars. It would be great if they did. I would love to buy a Ford, or Chevy, or Dodge Ram from them at their discounted, fixed prices. For that matter, I would love to buy, a Tracker, or a Nitro, or a Skeeter, or a Ranger from them. You are inferring that Wal-Mart sells low quality goods. You are wrong. Does Wal-Mart sell a lower quality ipad than any other store, or a lower quality flat-screen Sony TV?
As for your statement that a Tracker or a Nitro depreciates faster than any other boat, I would very much appreciate it if you could provide some factual information to support your claim.
Everyone likes to bad-mouth Nitro and Tracker, but no one ever talks about the fact that there are more Nitro and Tracker boats SOLD than all other companies. There's got to be a reason for that.