I think has something to do with experience and being around the welding industry. No machine comes with decent length leads or decent ground clamp. I was part of setting up a structural steel shop several years ago. We fab tubes (columns) for Wal-Mart at the time. We bought 8 Lincoln power sources (all 440) to run .52 wire (flux core). Two of the machines were used as stick machines to tack. None of the machines came with leads, clamps, or stingers.

Welding machine companies tend to stay away from selling cable. Hobart has a market with the chain store, and lincoln has a 100' or 50' package they used as a deal this summer if you purchased certain generator welders. With the copper market being so crazy I can't blame them.

Sometimes you can find deals for leads from Amazon at a good price.