Some people seem to think that Switching between Open and Solo is always about choice or PvP. It is not. Sometimes it is necessary simply to be able to play because of internet connectivity (I go to a hotel sometimes, or abroad where they have only satellite internet. I'm sure other people do too.)
The suggestion that it is just for 'cheating' as you call it is not even half the story. May I even be cheeky and say it is narrow-minded to treat the whole Solo/Open/groups thing simply on that basis?
I use solo when my children are using Netflix - 2 films streaming plus my game and my wife on her PC gives my little Sky box a headache.
Then when my friends are online later on at night, I go back in to our private group we made before release (all Beta backers).
But some in this thread don't care about that - they just want to "interact" with everyone, by force it would seem.