questions on discrimination and principle

I'm always cautious about wading into to some 'hot topics' on this blog, because it's not part of its purpose.  Having said that, sometimes I do feel the need to float ideas and more importantly to pose questions that arise out of an issue.

Hence, I am going to pose a question on the topic surrounding the recent B&B ruling, although it is not in reference to this case specifically (I did appreciate the gentle manner of Mrs Bull's response, however).  In my readings of the many opinions on this topic, I frequently come across the suggestion that because B&B owners are offering a public service, it should therefore be open to all members of the public and their practices, regardless of the personal religious belief of the owners of said public service.  Please correct me if that's a bad summary.  In some cases people have said that if they do not accept homosexual or pre-marital sex in general under their roof, they should not be in the business of offering hospitality (and by that I mean literal business, not just a general welcoming-ness).

My question is this:  for those B&B owners who do hold these deep beliefs which mean they are incredibly uncomfortable with the practice of certain things in their own home, are we then saying they should give up their business?  For those who have long-standing businesses, a sense of calling to this kind of hospitality wherein it is important to offer a lovely holiday to others, but cannot in all personal conscience accept, for example, homosexual practice in their homes?  Do we suggest that someone cannot start such a business unless they do so?

Where do we draw the line here?  It's a bad analogy, but I'll use it briefly - prior to the smoking ban, there were B&B owners who did not allow the practice of smoking in their establishment.  Now, you may quite rightly say - well, that's to do with health factors, the air quality, and how it affects other guests.  I did say it was a bad analogy, but surely for some owners it was a personal preference.  Likewise some B&Bs  did not personally want people bringing their pets into their establishment, not just for the sake of other guests but because it was their home.

My point, however badly made, is that decisions are made on personal principles all the time, including in the hospitality business.  My question, I suppose, is are we to consider that personal beliefs and preferences are unimportant in these areas and even unacceptable?  That we can no longer officially do things on moral principle?  That the private should never influence the public? Because frankly, we do not all hold the same principles and no group, religion or government will ever be able to force us to do so.  And I wonder if deliberate discrimination and personal principle are occasionally getting mixed up, when I don't think they are necessarily the same thing.

These are my current ponderings and I am not submitting an argument or an answer.  Neither am I commenting on legality and law.  But I can't get rid of the questions - hence I'm throwing them out here out of genuine interest in peoples' response.  I'm interested by the relationship of the private and the public, of belief and practice, of how we deal with personal principle - these things are abstract, but they impact our thinking on such issues.  Again, these questions are not particularly specific to the most recent case, but neither would I necessarily apply them to other areas.

Feel free to disagree - but please be respectful and remember I am asking a genuine question, rather than delivering an argument.