For some strange reason, the percentage of cookie makers who like putting raisins in their cookies is far higher than the percentage of cookie eaters who like having raisins in their cookies. It is like there is something about raisins that make them more enjoyable for bakers to use than any other ingredient on earth. I suspect this may have something to do with people learning to bake from their grandmothers, who baked back in a time when chocolate chips were not as readily available as raisins.
Thankfully, we all now live in a world where chocolate chips are as readily available and inexpensive as raisins. Since chocolate chips taste objectively far superior to raisins, if you want to serve cookies at a party that most people will really enjoy, you should use chocolate chips instead of raisins.
Curiously, nobody ever puts raisins in plain cookies; it is only ever with oatmeal cookies. It appears that people may be misunderstanding the nature of an oatmeal based cookie and look at it as a health food rather than a treat, but oatmeal cookies taste just as good as regular cookies. If you put out plain oatmeal cookies with regular plain cookies the oatmeal cookies would eaten first. You can tell this is the case because while you can find oatmeal cookies, you will very rarely see a plain cookie for sale; they need chocolate chips in them in order for people to buy them.
Two things you need to realize are that oatmeal cookies taste better than plain cookies, and using raisins will at best make the cookie only slightly healthier than if you used chocolate chips. Adding the oatmeal to a cookie is what really increases the healthiness of the cookie and it does so without making the cookie less appetizing. Raisins are healthier than chocolate chips, but they are high in sugar and calories, which offsets some of its benefits, and when you factor in that most people don’t actually like raisins you are better off sticking with the chocolate chips.