I don't see that as oxymoronic at all. Far from it.
Aspirational Fe typically means that emotions are focused on very few individuals (possibly even only a single person), but when they exist they are of an extremely rare intensity and purity.
I am a strong INTP, and I'm not sure I know anyone more romantic than myself. I know I'm more romantic than my INFP mother, and way more romantic than my INTJ father or especially my (ISFJ?) sister. When I finally expressed my feelings to my (unrequited) first love (and now, years later, good friend), an INFJ, I got the impression that she may consider me more sensitive and romantic than she is.
In general, introverts desire more intimacy than extroverts. In the Eysenck model, introverts are those with high default levels of cortical arousal, and extroverts low levels. The Yerkes-Dodson law shows that humans (and other animals too, I think) are more comfortable and productive under moderate arousal/stress. (Well, technically, over-stressing causes no detriment in accomplishing extremely simple tasks, but those are rare in the real world). Social interaction of any kind can be a significant stressor, but strangers cause far more cortical arousal than close friends. Everyone needs and craves some social interaction, but strong introverts need to limit this to a few intimate friends rather than large groups of acquaintances in order to avoid the sort of stress on which extroverts thrive.
I'd guess that romance is also strongly correlated with Intuition (of either attitude) and Extroverted Feeling. There is some Introverted Sensing correlation too, especially when it comes to reminiscing about meaningful events in a couple's past and recalling how one felt but also when it comes to cliches like bringing flowers and chocolates. I think it may be my strong Tertiary Si and corresponding nearly eidetic memory of emotionally resonant events that can give me a romantic edge over an INFJ. A highly stressed INTP would tend to shift towards the use of Si and Fe, making him more conventially demonstratives of love if he has a partner to whom to show it, making hard times more likely to bring a couple closer together instead of tearing them apart.
I've read before that while NFs (especially INFJs) tend to be the most loyal and committed to their current relationships, NTs (especially INTPs) tend to be the most loyal over the course fo a lifetime, and have the hardest type abandoning a lost love. NFs tend towards serial monogamy; NTs, true monogamy. I also read a study showing many traits associated with Intuition to be strongly correlated with a desire for monogamy in men, but there was no correlation among women. It claimed the lack of the trend in women is because society teaches women to be just as mongamous, but I wonder if it might also be because most N women are NFs instead of NTs.
Not that I put much faith in Enneagrams, but INTPs are typically 5w4s in that system, and 4 is strongly associated with romance.
