I have no problem with people that decide not to have sex with a HIV+ person with a undetectable viral load, as long as that same people will have the same level of scrutiny and also deflect potential partners that, for example, don't know their status or have engaged in sexual relations without protection even though they don't have any symptoms or reason to believe they are infected by anything.
But if you are willing to give people with unknown status a pass then that does rub me the wrong way, because I can't understand your logic. If that level of risk makes a difference on whom you find acceptable to sleep with, then there is no reason why you should be sleeping with people that don't get tested periodically (and let us be honest, who does?), or who don't know their status.