Ya ... I've seen dirtier ones.
How many miles on the bike in question?
I have used the same OEM replacement filters for 60-70,000 mi before inserting a new one. I'll remove the used one and hold it up to a light source. If I have a hard time to see light through it, I'll discard it. Otherwise, I'll turn it upside down and gently tap it on a hard surface to loosen any dirt/debris. Then I'll adjust my shop air to 65 PSI and blow out the filter element from behind and re install it.
At least you didn't find any nests, or other signs of critters inhabiting the air box!
Now that the weather is starting to warm up a bit here, I'll be starting my spring preventative maintenance ritual. I have to instal another set of t-belts again and change/flush all fluids etc.
Dusty