That is a bold statement to a degree. I feel from owning a lot of black vechichles in the Northeast over the years that if you take care of your car and clean it from time to time it will be fine. Rock chips happen in any car, just black shows up more, but depends on how much highway driving and angle of the front end of the vechichle. Dirt is dirt on any car, but again just shows up easily on a black or white car.
If you don't take care of them like my parents did with their eclispe and cavalier, both black, they will fall apart. The cavalier had so much rust I thought it was gonna fall apart! Strong engine though and they bought it new in 94 and drove over 210, 000 miles with nothing ever wrong with the engine, but the body because they cleaned it once every few months and detailed it once every couple years it fell apart. Plus it had well over 150,000 high way miles.
The eclispe, which I ended up buying off my parents and had repainted was more due to the paint from the factory of Mitsubushi. Parents had it in their contract and paid extra when they bought the car if it had any major rust, paint problems it would be repaired for free. Well 2 years later it was pretty rusted and they painted it for free. How long it lasts is beyond me, but I just sold the car in early summer.
I did have an s10(over 30k) all black for a few years and never had any rust (Which they are known for) or many paint chips. Did have the side repainted due to my Dad borrowing it and hitting a wall, lol! But the truck always shinned. Also my current car which is a 2006 Ford Focus St is in great shape still and will be two years this Feb. No chips, nor any problems with the paint. I clean it once a week and detail it every 6 months.
Will say they do get dirty easily, but it all comes down to how much you want to take care of it and how much highway driving you do. A lot can factor in to it. Just because you don't like black cars and is pretty much your opinion shouldn't make you state why do you want black? Maybe he likes black vechichles. I do as well and when cleaned up, nothing looks better in black IMO.