Here's my take on it, but bear in mind I'm no lore expert. I've only watched the movies, done extensive reading on Wookiepedia (like...EXTENSIVE!) but have never picked up a novel or comic. If I am ignorant to something specific, feel free to point it out - but I reserve the right to dissect/debate all the same.
My understanding is that this is a point of active debate among the Jedi, but that the "in favor of relationships" are very much the minority, or at least they seem to be presented as the minority. There are a few that have them, and there are a few that harbor feelings for others, and there are more yet that have said feelings but do not act on them. And all of this is fine, nobody (at least I'm not) really says that all Jedi should up and get married. Even if it were more accepted, I still feel that most Jedi would likely elect a life free of deep emotional attachments.
I get the self-sacrifice argument - really, I do, but I feel that Jedi are self-sacrificing as it is. They do not generally seek or receive vast wealth. Dooku, for example, chose not to inherit his family's fortune until after leaving the Jedi order. That was a sacrifice he made, in my opinion - he could have been loaded rich!
They also thrust themselves into danger and always place the fate of the galaxy and its people before themselves. This is not, in my opinion (and several Jedi, I'm sure), mutually exclusive toward loving someone on a personal level. You can do both, and the Jedi order would have been better off, I think, grooming people from the young age they're trained, to find balance within this. How many stories have you read where a loved one dies, the one left behind swears revenge, but decides on a greater purpose because it's what their dead loved one would want? (Plenty still go for revenge, but you get what I'm saying, hopefully.)
From the -original- incarnation of the Jedi code, too, it seems more about balance to me. There's none of this "There is no ____, there is only ____" black and white view of everything. I interpret the original to basically acknowledge that certain things exist and obstacles come up in life, but that you find balance within them, and overcome said obstacles. The most relevant line here I suppose would be "Emotion, yet peace." To me it acknowledges the existence of emotion, that they are a thing and you can have feelings for a person. But that you do not let them dominate and dictate you, and you still strive toward an ultimate goal of peace where emotion still exists.
Could break down the rest of the code the same way. "Ignorance, yet knowledge" not outright rejecting ignorance/ignorant persons, but acknowledging that it exists in the galaxy, and trying to rise above it through knowledge, education, wisdom, debate, etc. "Passion, yet serenity" - passion exists, but same as before, not letting it dominate and rule you. Not the same as outright saying NOPE, EVER EVER IN A THOUSAND YEARS! "Chaos, yet harmony" - chaos is everywhere in the galaxy, yet despite seemingly overwhelmingly odds, still striving to create harmony both within yourself and for others, as best you can. "Death, yet the Force" - death is a factor; people die. This to me is about accepting that fact, and embracing it, not feeling overwhelmed by loss as people (as Yoda put it) "become one with the force". Really, to me, everything is about -balance-. It is not meant to be black and white, and I feel the re-writing of the code (to its form in SWTOR, that is) does it the injustice of making it very black and white and goes against the nature of its origin, and it's something my own Jedi would often point out - that its original form felt more enlightened, "there is no ____, only ____" embraces ignorance and black&white rather than enlightenment and balance. Which is ironic, because one of the lines is directly about ignorance.
(as a note, this is not a criticism of Bioware or anything of the sort - this is purely from a lore standpoint and I am saying the choice, by the Jedi, to rewrite the code did its original form injustice. People make mistakes.)
When it comes down to it, I think that in the some of the cases even during the more strict years, I think it was a matter of while frowned on, no Jedi would really go to the extent of persecuting someone, stopping them by force, arresting them, or generally exiling them from society.
Much as they could unintentionally make people feel like crap for having feelings at times, they wouldn't really rail against it so hard that it might turn someone into hatred and make an enemy of them. Everyone has their own path to make - and so long as they're not outright hurting people, I don't see them getting hardcore about it, though certainly uncomfortable - maybe at most politely asking them to step down from the order, and even that I think would only occur during especially strict time periods.
Obi-Wan loved Anakin like a brother, he was saddened over the loss of his Varactyl, he put aside his emotions to fight Anakin....so yeah...Jedi can have feelings and emotions, they just can't let them be in control.