Well the rules apply to solo the same as they do to any other mode but unless a player is going to report themselves it's very unlikely that anything will be done. If they ever do implement some form of automated policing of it though it obviously
should affect solo in the same way as any other mode and that would be a
wholly good thing unless you happen to be someone who believes that games should be completely devoid of any negative consequences, thereby rendering the traditional risk/reward equation completely irrelevant. I don't really grasp what satisfaction people can find in that.
I mean in solo the only thing that is ever going to kill you is
spectacularly misjudging a fight against an npc. Not sure how long you've been gaming (or whether you took the same break between about 1999 and 2014 that quite a few people posting on here seem to have done...) but it used to be the case that the only two ways you could avoid a death in a PVE based game were either the fabled git gud, or by using a godmode cheat. Ooh look, it's that word again.
That's leaving aside the fact that as several people have mentioned, solo =/= single player mode. You're still affecting the BGS in solo.
As for 'social multiplayer', there is no social-only multiplayer mode, so that leaves you with the two existing multiplayer modes. Of those, if you can find a bunch of people who want the same experience as you you can play exclusively with those in a private group and make up whatever rules you want, although
even then you shouldn't be combat logging because game rules have precedence over any individual private group's rules.
If you're in open though, yeah you can play 'social multiplayer' if you want but you need to accept that some other players may want to play differently and no matter what your opinion of their playstyle is, it does not give you the right to ignore game rules.
Nothing gives you, me or any other player the right to ignore game rules.
I honestly have no idea why this is such a hard concept to grasp because it really is the
absolute frakking basics of playing with other people.