@DizzyCrash: No.
I'm saying that bedrooms, by themselves, already are dwarves' default idling places if they don't have other things (taverns, temples, statue gardens, etc.) to pull them away from them, and that others have used this fact to make segregated family compounds.
You can even use four screw pumps surrounding an idling tile if you want. Locking two in a room is also still effective for pairing up particular two dolls you make kiss each other, but now you know how room them together better.
So, it's quite possible to get friendships, marriages, grudges....Or almost no relationships at all as you observed, depending on how one setups things. For those who played in .34 days and want dwarves who don't know each other for mental stability, ability to choose between the two is convenient.
The inconvenience is for those who want grand taverns, full of beauty and wealth, with plenty of dance floor, observed by all, yet also want relationships. There is a trick with disabling the meeting zone part without unpausing after one defines the zone as a location as to not make it the default idle area that pulls dwarves from everywhere, but large dances and dance floors are unavoidably going to result in hardly meeting anyone.
Also, just like PatrikLundell suggested, I've also built my beds in the main dining room and gotten pregnancies and marriages in 42.06 3 years ago, in one of my first few forts before joining bay12. Though I did that to maximize room value (as the room value penalty is applied just once), not for relationships.
The main issue with doing that is, again, beauty. And greater danger if visitors go hostile, I suppose.
As for planning to fix, I do think there's an open issue on bugtracker somewhere...
8584. I think there might be another one on "dwarves don't seek out friends when lonely"; dwarves not fulfilling most their needs (all other than drink/sleep/eat/clothes/Tasks!) is widely considered a bug at least.
44.11 Stress and Psyche thread is a long read that considers both this, above and other factors.
For fixing that particular behaviour yourself, I'd say feel free to hack it in. I don't think Toady One is going to fix that in, spitballing, next four years, at least, provided "seek someone out" from corruption isn't generalized for all tasks (0,5 for villain arc, 1 for steam, 2,5 for mythgen). The upcoming small changes mean, as far as I've read, that it is a little easier to set up pairs between dwarves and that you can get kids out of wedlock, so probably sooner than before - no mention has been made on friendships.
But this is lot of years without DF and lot of talk as well. For bettering your own understanding, I recommend just making quick and dirty tiny sealed-off forts in 44.09 (less emotionally fragile) with variety of different taverns each but with same dwarves, running the game for year(s) at 4k+ fps, and watching which ones result in no relationships versus lots of acquitances versus few strong friendships and marriages.