All arts organizations have to raise money and they all have different ways to do that. San Francisco Symphony, for example, has a new music fund and a visiting conductor fund, among others. If a donor has a particular interest in those areas, she might direct her annual donations there rather than to the general fund.
SFS and SFO and every other orchestra and symphony raise money to endow player chairs. An endowed chair is essentially paid for in perpetuity because the endowment interest pays a large part or all of the salary and benefits of the player occupying the chair. The BSO has managed to endow almost all of their chairs; this greatly increases their financial stability and frees up donated money for other uses. It also means they're very, very unlikely to wind up like various orchestras (Cleveland, Philly) that are in financial hot water.
SFO has a great singer fund and a fund in support of Italian opera, and various other specialized funds. They have these funds because there are people willing to give to them.David Gockley has made it a priority to bring the best singers to SFO, and I do not find that objectionable: the quality of the singing during the Mansouri and Rosenberg years was pretty variable.
The singer fund makes sense to have because 1) SFO's singer fees for principals just caught up with the rest of the world, and it makes sense to be competitive 2) We are at the far end of the world for singers who live in Europe. Anyone wanting to see Jonas Kaufmann sing at SFO (perhaps in the scheduledTroyens?) can increase the chances of him turning up here by throwing a little cash at that fund.
As far as Flicka goes, they asked her to front this particular campaign because she's a great singer and is well known to be the nicest person in the world. A personal appeal from her has meaning and goes a long way. (She also has raised goodness knows how much money for St. Martin de Porres Catholic School in Oakland, which serves a low-income population and has a great music program in part because of her support.)
I am not personally perturbed by any of this, and goodness knows, I'm always ready to make fun of an organization that I think has blundered in some way. Whether I donate to this fund is beside the point, but I think the opera is smart to find as many potential ways as they can for donors to feel good about where their donations go.