I have a daily commute of about 4 miles and have ridden on a handful of different saddles - Brooks B17 Standard, Selle San Marco, WTB SST Comp - and have always worn through the seat of my jeans. To be honest, I have found that the amount of wear and tear to your jeans depends more on the quality and fit of the jeans than anything. Also would suspect that this is much more pronounced on road bike commuters than hybrid commuters since the more upright you sit the more padding you will have between the saddle and the pelvic bone, which is what I have found to cause the wear.

My wife has designated my jeans as either bike-riding and non-bike-riding pairs so I don't have to worry about it.