Over the a 20 year life time, as mentioned, I think 60 washings is a low number of necessary washings. Example, sleeping bags: Usually these are washed about once every 15-30 days. I usually get out 60 days a year, which means that I launder mine at least three times per year (usually 4-5 because they also get dirty from trail dust and mud splashes besides just body sweat.) So 60 times per 20 years is probably a low number. Jackets get worn a lot more and are laundered every trip. Because these are worn around town, too, launderings are closer to 8-10 times per year, or about 160-200 times over 20 years. Others are probably not as concerned with dirt and odors so they might launder less, maybe 3 times a year. 60 seems a reasonable number over 20 years.
True, that many on BPL think newer is better. I don't subscribe to this concept. It is sometimes better, but often it is just newer. Good 800 fill down has a LONG lifetime. Unless it is mis-laundered with detergents, too much soap, or otherwise physically damaged, it will last a LONG time; 20 years is around the MINIMUM I would expect such items to last. So, I look at stitching (synthetic vs cotton,)zippers (plastic, waterproof metal, stainless steel, brass or bronze,) seams (rolled vs overlocked vs single stitched vs double stitched) and other things like the amount of down (loft, weight) vs temperature. Down garments and sleeping bags should be considered as a durable good, unlike synthetics that can mat loosing insulation over time. I will pay in extra ounces for good shells, good zippers, and good design knowing it will be around for a long time. I will use it till something happens, forcing a new one to be purchased. Hence, I buy the best I can...it makes sense to me.