Yes, but it does that on a voluntary basis
Some people find some activities more enjoyable in open with oposition.
Some do not.
And as it is now, both player types can enjoy the game.
So it's all based on personal choice not based on forced open only or by penalizing players for certain play choices (as in playing in solo)
The choice is to make NPCs much harder (so hauling is not 100% efficent in solo / PG) or to let players do it. Either way, defence needs to be harder and attack easier- the worst way you could do that is by upping the numbers and making it even more grindy...you need something else to attenuate the problem.