I've heard it said that philosophers as a demographic are overwhelmingly single (in the unmarried sense). I don't know if this is true, but if it is, could it be because love and reason conflict? For example, if your lover has a habit of losing valuable items, locking him/herself out of the house, etc., practical reason forces you to confront them with suggestions implying "you ought to be better - I'm telling you how you should be better", a suggestion which is often infuriating to someone who's supposed to be in an equal relationship with you. Love, on the other hand, urges you to look with forgiveness and even humor on your significant other's faults. Given these consequences, if you're agreed that love and reason pull us in these separate directions, shouldn't humanity focus on love and forgo reason?

I think it's true that philosophers tend to be single more often than non-philosophers, but I'm not sure I would attribute that to their being bound by the dictates of practical reason to regularly and overtly draw the attention of their partners to their moral or prudential failings. It may rather be, perhaps, that philosophers are on the average more argumentative, more idiosyncratic, more perfectionist than other folk, and more needful of personal time and private space for reflection and writing. But going back to reason, I think there's no good argument that a commitment to rationality, which we'll assume no respectable philosopher will shirk, requires one to act as a monitor and corrector of those around one, especially those one loves, since as you suggest, love is more important than being right or improving others. That isn't to say that you should never try to modify the behavior of others for the better by your own, presumably fallible, lights, and in ways that will also benefit them,...