i absolutely hate wrinkle finishes on toolboxes.
all my machinist boxes, and my 1st set of mechanics boxes were kennedy
they always look dirty to me.
What you experienced is not at all an anomally as the dirt and dust does indeed get trapped in the texture no different than dust stuck in a stucco wall.
Unlike std. dust tho, dried bondo dust, paint overspray, etc. cures and hardends over time so getting it out, even with solvents, is a *****. Add in metal grinding shavings or sand grit and there ya go. Do work with a lot of Sika Flex , black silicone caulks or anything else that is not water based or is solvent resistant and the texture tends to eat that ^%$ up and hold it but nothing will remove it without scraping or major scrubbing. But razor blades are not an option on a textured finish.
Unlike a smooth finish, no razor blade or even scrub brush will work in many cases.
Buy what you want folks, I just am suggesting from experience.
For a basement or garage box, no biggie. For industrial or shop use, it's not so much what you do but the environment that it is exposed to that fubars it.