My point is that you have a simplistic understanding, i.m.o., of the choices any private party has with regard to serving the public. It never means the universal public, necessarily. A provider can limit services, and can limit the population he/she serves, for all kinds of reasons. I provided the example of the OB-GYN because age discrimination is a frequent civil rights complaint, and I am telling you that businesses whose focus accidentally results in discrimination by age, sexual orientation, marital status, and even gender (when not a gender-specific business, such as NOT an OB-GYN) are protected by the fact that they announce first of all whom they are serving, exclusively, and secondly by informal, unpublished choices they make.
Smart providers do not announce what they limit, if they believe those limits will be challenged, and I definitely support such decisions on their part. And I’m sorry, but if you think they do not get away that, then your experience is, I believe, much more limited than mine.
Simply, “I don’t have the capacity for more customers/clients at this time” covers a whole host of reasons. It’s a subjective judgment which is protected by being a private provider. And no client, patient, or customer, has blanket privileges to invade the privacy of other clients or patients, especially in medical situations, given privacy privileges/rights which trump activism every time.
Another example: Supposing an OB-GYN had in fact occasionally done IVF and other fertility procedures for straight couples, and that same doctor has a single lesbian for a patient (has had for some time), who announced one day that she wanted to be inseminated with his professional assistance. He could simply tell her that in his professional medical opinion, insemination for her would not be a good idea, and he could not be party to that. However, he could refer her to other providers who might provide that.
Of course, the paragraph above is not entirely realistic. Why? Because normally homosexuals, both single and coupled, specifically seek out “gay-friendly” providers. Lesbians in particular prefer female Ob-Gyns, often because they don’t trust men, often because they consider female providers more friendly to them, more trustworthy, and sometimes with an interest in “rewarding” (supporting) “gay-friendly” providers. There are official lists of these on various websites in those communities.