Obviously, the K&N captured contaminants that your parts washer filter didn't. You have stated before on many occasions your disdain for K&N products.
It's only obvious in your mind. The filter was the same color when I got it and the parts washer didn't make it any better, or worse. I already told you I didn't get it new.
Further, you are just making ridiculous suppositions/accusations without any basis in fact. I use K&N filters in my CB750s filter box. Hardly a disdain proclamation. K&N doesn't make a filter to fit inside the 550's stock air box. I believe they used to, but they abandoned us due to profit reasons, I expect. So, I use Uni filters there, because I want a reusable filter for economic reasons.
I prefer bikes that don't misbehave in bad weather. Bad weather is enough of a distraction without nursing a poor performing engine through it, instead of concentrating on traffic and safety matters. An exposed filter is not prevalent on any production vehicle because of the compromising effect weather has on it.
If I had a need for a machine that only saw use at the track, an exposed/unprotected filter on a modified engine that could take advantage of it, might be a consideration. I really don't give a f*ck if my bike doesn't win some superficial cafe lounge show, because it doesn't have the most desirable fashion filters installed on the carbs. Why people think filter media is attractive is beyond my comprehension.
Have you ever wondered why K&N hasn't gotten any major manufacturer support for production vehicles? Were they as superior as you wish to believe, why can't they convince a manufacturer to incorporate their product as OEM equipment? If they could really deliver increased performance and reliability, I'd think the manufacturers would gladly include such a part in the production build, at least on their high performance offerings. But no, even K&N's highly refined marketing and advertising campaign leaves the major manufacturers unimpressed, or unconvinced of it's worth. If I have a disdain for K&N, it is directed at their marketing strategy, and misleading advertising. They are long on promises/innuendo and short on factual, relevant data. However, they have tailored the advertising to the individuals most susceptible to give them money, the home mechanic with high hopes and little to no aptitude for differentiating true needs and capability. Real engineers are knowledgeable of the concept of "trade-offs". Home mechs think everything changed is win-win (and looks cool).
If you operate your engine where there are no airborne particulates, you don't need a filter at all.
If you don't mind changing your oil more frequently as it collects airborne dirt, then use a filter that doesn't collect all of it from the incoming air.
If you don't mind shaving the operational life of the engine in trade for a "higher HP" dream, then use a minimal filter, if any.
If you are out playing in dusty dirty environments without proper filtration, then prepare to sharpen your rebuilding/ replacement skills.
I'm willing to trade extra maintenance activity with less long term cost, for the convenience and higher cost of the disposable paper air filter, even though it is almost certainly better at actually preventing dirt from reaching the engine (particularly during periods of neglect).
Once an oiled filter has it's membrane fibers coated with particulates, it either becomes very restrictive very rapidly, or it becomes ineffectual at trapping particulates.
