I hope I'm not too late, but I'll dump everything on my mind.
I don't see why a map being ranked and a map being Loved have to be mutually exclusive. Aren't there plenty of maps out there already that are not only loved, but also are ranked? I'm probably projecting, but I think something like Freedom Dive should be Loved, even though its already ranked. It has 1000+ favorites, too. But for those Loved maps that can't be ranked, the warning with the "This Loved map will not give pp" can just flash before you play the map.
I agree with what several others have already said, including that the Loved category should be full of things that are genuinely loved, like a priceless treasure. That said, there could be two ways that a map can be Loved:
1. A point-based system, where a favorite counts as two points and a kudosu counts as one point. Additionally, any amount of kudosu from each user only counts once, only allowing anyone to contribute a maximum of three points to the map. I understand the important of kudosu, but allowing kudosu to have too much influence over whether a map enters Loved or not could be easily abused. Then, a map has to reach at least 250 points or so to be Loved.
2. A voting system, probably 2-4 times every year, allowing the community to put in any beatmap for entry and to vote on them. The primary purpose of this is to get loved older beatmaps that have little/no favorites and beatmaps with inactive creators to become Loved, if the community wants it.
There may be other ways that I'm not really thinking of, but any method of getting a beatmap into the Loved category should have a significant part of the community play a large role in determining the result and not by any small group of users.
That said, maybe there can also be a new category of beatmap, "Notable", to allow mappers who want exposure to get what they want. I'm not too confident about how this would work, but you could probably just rename the current Loved category to this and it'd be okay for a while. I think this would work because I am of the belief that the only reason Loved is a goal for mappers who want exposure is because its an entirely different category which much fewer maps than the Ranked & Approved category, allowing their work to stand out more against the incredible amount of ranked maps present. My belief could be entirely wrong, though.