Good point @a_c_green . To expand on that, if you take the time to report those buggy whip listings that raise red flags, one could argue you are also possibly benefiting other competing buggy whip sellers as well.
If the net effect is that the category as a whole gets cleaned up and becomes more of a level playing field with less fraudulent/policy violating listings, the person doing the reporting isn't the only one who may stand to gain from that and may in fact be helping out their (legitimate) competitors as much as themselves.
Not to mention the most important thing - getting rid of scams makes eBay an overall better, more trustworthy place for buyers, which should be extremely important to all sellers regardless of category.
If a buyer gets taken for a ride on an eBay purchase for a buggy whip, it is far less likely they will come back to eBay when they are ready to purchase that ice cream maker. Reporting the red flags we are most likely to see in our particular niches hopefully benefits the whole marketplace in the long run.
