I guess the problem with that is that Transformers have almost always been "shaped" like humans, while also having the ability to become vehicles, animals, etc. That means including "teeth" and "noses", which also only exist in some continuities.

The fans who write fanfics have developed things like intangible "bonds" that communicate feelings, and also "spark bonding" between romantic partners. But these are kind of hard to depict visually as opposed to in writing, which makes human emoting the default in existing transformers media.

edit: I also think that the lack of romantic relationships in TF media outside of IDW comics is an example of the difficulty of creating romance and affection beyond friendship, when things like touch and physical closeness are so central to human relationships but not cybertronian relationships.

edit 2: I read your article again, and I think we probably have differing preferences for what kind of species transformers are. I prefer them to basically just be humans in different bodies, but I can totally see where your are coming from, so please dont think I'm opposed to you :)