I play in Solo pretty much all the time, since that is how I played Elite and Frontier II in the 1990's. I was disgusted when they dropped Solo Offline play, as this was one of the Kickstarter items I had requested confirmation about before committing funds. Occasionally I play Private group with a colleague from work, but typically we're scatter light years apart so that meet ups in space can take forever, before we can fly as a wing.
Open play typically too much grief and with insurance at ~5M a pop for my current ship, such that it can be hours of play to recover. AND if it happens around a Community Goal, you could be killed multiple times before you make enough to recover costs or see a faction back from the CG reward. One on one PvP grudge fight sure, because both agree (guess this is why Arena was created), but when you're solo and get jumped by a wing it just frustrates. I play to get away from stress of work, not find more stress.