Hi, I'm a Financial Advisor, and though I don't specialise in the Gay community I know a lot of advisors who do. As per the earlier answer, there are slightly different considerations when looking at a gay couples finances, though also when it comes to life insurance and health cover there are (or at least were until very recently) some life assurance companies who would assume that gay men were at higher risk of HIV infection and these advisors used their experience to know either who didn;t ask in the first place, or who wouldn;t be biased against gay men (I appreciate that gay men are not at a greater risk myself but some insurers seem to disagree!).
Another consideration is that though we live in relatively enlightened times, many gay men would rather discuss their finances with another gay man, in much the same way that a lot of women will seek out a female advisor.
A further point though, as made in an earlier answer, is that some advisors want to target "The Pink Pound" as stereotypically, gay men are seen as having a higher disposable income as they (again stereotypically) don't have kids! The more money you have, the more commission an Independant Financial Advisor can make from you (not that that's necessarily a bad thing, as if IFA's don't make any money and go out of business who are you going to get to sort things for you? Your bank!! HA! They'll never give you the very best deal!! (Excuse the rant))