Speaking in terms of canon only, I dislike it. I’m also one of those fans who thought it was neat that the Doctor was so explicitly aro/ace. I’m not someone who thinks there’s too much romance in media (I love romance), but it was refreshing to find a character where their lack of interest in sex and romance was seen as a normal part of them. It isn’t shown as something that should be changed, and none of the other characters try to force anything on them (generally).
By giving the Doctor sexual and romantic attraction, it lowkey removed the mystique for me. Now he’s less like an alien who is entirely unaffected by the whims of their “little heads”, and more like a normal, quirky person who happens to own a spaceship. I understand a lot of fans want their fanservice and representation, but that’s what fandom is for. Write fics! Draw! Gush to your friends! You can give the Doctor all the relationships you want without having to worry about if the BBC or Big Finish will present it to your liking.
Was it a necessary development for the modern series to appeal to modern audiences?
I think so, unfortunately. New Who is vastly more popular than Classic Who for (many) a reason, and shipping is what propelled Rose and Yaz (and now Rogue) to their heights. Doctor Who wouldn’t be able to sustain itself if they’d stuck to their 20th century status quo. Fandom these days is primarily hinged on shipping, and the Classic Who side is the only decently sized fandom I know that actively eschews it.
Is it handled well by the production teams?
Speaking objectively, I think so. I don’t like the Fifteen/Rogue relationship, but I don’t mind too much how it was done. Same for Rose. I can understand why some may have felt baited by Thirteen and Yaz, but, again, if the Doctor would’ve just been left as aro/ace, none of that would’ve been an issue. Ship Thasmin however you want in fandom. Doctor Who is a sci-fi, not a romantic drama or a snog-a-thon.
A lot of the fun in shipping Six/Peri for me comes with the fact that isn’t canon. If it were to ever be made official, I don’t think I would like it because it wouldn’t fit the ideal I’ve created in my head (because it’s a family-oriented sci-fi and not a romance…). But fandom these days wants everything handed to them for some reason. They want the writers to write for them, instead of for the show itself.
And River? Her relationship with the Doctor is handled atrociously.
Has it always been there, but just hidden until more recent times?
Yes, it’s just a matter of if you want to see it or not. In my view, Six and Peri have sexual/romantic tension in the show (and in audio). This isn’t expressed outright, but if you want to see it, it’s there. If you don’t want to see it, they just look like close friends. And this goes for other Classic Doctor/companion pairs. If you want to read between the lines, you can imagine anything. If you don’t, it won’t ruin your experience.
New Who is the complete opposite. They force you to see the romance. There is no room for interpretation, and that’s what I dislike.
Does the expanded universe develop these aspects further than TV ever could?
I can only speak for Six and Peri, but the audios definitely play up the fanservice/shipping aspect of them. There are innuendos in a lot of the audios that are either straight up sexual or allude to flirting; and there are storylines themselves that, if you want to read between the lines, can be interpreted as romantic. I like how I am able to analyze these elements how I see fit.