FFXIV is similar to other MMOs now where you have dps, healers, and tanks. There's no "support" role really. Bard is classified as dps, and has what are essentially party/raid buffs that are a part of it's role in a group. If you have the choice of doing dps or doing buffs, the answer is that you should be doing both.

Please, for the love of god, don't queue for a group as bard and then proceed to just sit there singing songs while doing nothing else simply because that's how it was in FFXI, or how you envision a bard to be.