I think it's more normalized because it's shown that the dragon thinks and communicates in the same way as a human (can make jokes, be thoughtful, even rude). Therefore, their bond with Mordred develops as any other would. They are not seen as a pet or a lesser being, but rather a friend. Which would mean, considering a lot of people fall in love based on their partner's personality, that it would not be strange to fall in love with a dragon companion. Although I'm not going to pursue them myself, I find it less weird due to the way that the dragons are established in the story! Hope that clears it up a little.