Hypothetical situation: Let's say I'm an atheist and I'm asked to advertise/design/create something for a Church or Christian organisation, could I do it? (I could be designing an atheist poster, but I think atheist posters are rather improbable.)
Or let's say I'm a vegan, could I design a corporate identity for a butcher? If I'm a feminist and asked to create a brochure detailing male accomplishments. Or a nature lover asked to design something for an oil conglomerate, would I do it?
I can of course, decide to do it professionally, separate my own personal views with that of my job's. But in a creative industry I think success depends on your ideas, and idea generation can only be possible if one is compelled, driven to think creatively. I might try all I want to think of ideas for a Eat Dog Meat advertisement, but you know what, I think the ideas I'd come up with would be generic, lousy ideas at best. Because I wouldn't want to create a Eat Dog Meat advertisement in the first place, I personally would much rather want to create a Don't Eat Dog Meat advertisement, and I think thinking of creative ideas for such a cause would be much easier.
I think my conclusion is that it's rather impossible to advertise/design for a product/cause that you are against. There are of course, many products and causes that you are neutral towards; I wouldn't have any problems designing for an umbrella shop (purely hypothetical because at point of writing, I don't know any shop dedicated to selling umbrellas). There are also products and causes that you are passionate about, I would definitely be interested in designing for a camera shop, but usually you don't run into such opportunities very often (which is why I have not designed for a camera shop).
But for products and causes that you are against, that's the hard part. Is it possible?
I think the weirdest thoughts start coming to me around 4 in the Morning.