It changes the steering axis in my opinion and upsets the geometry as designed. Adds increased leverage loading to torsion bars and lower arms and ball joints. All this and the bearings as you mentioned. The steering axis is the line drawn through the ball joints to the point the tire contacts the road. That would be in the middle of the tread width as designed. Moving the wheel assembly outboard moves the steering axis inboard on the tire. Hitting a pothole then wants to pull the wheel outboard adding shock to all steering linkage parts and box. You will feel added "dart" through the steering. Imagine standing with your arms rigid out to your sides. A person could walk up and steer you with one finger. Add to this the front drive and increased grab on one side adds toe in force steering direction action as more rubber is outboard of the neutral axis. Many say spacers are great, but we get used to things and think that they are normal. The wider track may provide some marginal stability at the expense of all the above criteria. Dave Lenzi who rebuilds the front hubs and gives a seminar, will point out the added incorrect vector forces the narrow bearing pack has to support in a direction it was not really built for. My 2 cents. Just common sense