@Smoky - That’s an artifact of the casting process. As the aluminum is exposed to dirt and oil and it oxidizes, the small nooks and crannies trap all those things and make the surface defects more noticeable.
What you see is the result from an aging tool. The die cast tool used to produce these parts is probably good for 100k parts, give or take a few. The tool is made from tool steel, and every injection of molten aluminum and the following solidification will put the tool thru a hot/cold cycle. After some time, the surface of the tool will develop small cracks. These cracks fill with aluminum during the casting process, leaving the marks in the part when it is ejected from the mold. The older the tool, the more cracks you will find. Eventually the deburring process for the parts to fulfill quality specifications will be too costly. This is the point where the investment in a new tool makes financially sense, marking the end of life of the old tool.