For what it's worth, the issue is not about whether or not a GPS is good or bad. It is more about what people do when they are flying and their ability to look out.
In my gliding days I have painful memories of my instructor in the rear seat bashing me on the ears when I didn't look before turning. We were also trained to look for other gliders circling (amongst other things) so we could find thermals or signs of potential lift. At the same time we would need to know where we were to get either back on track or to our destination. All of this was before GPS was generally available.
I contrast this with my experience in the world of powered flight. Very few people have a decent lookout, partly because of limited visibility but often because it is not taught at all well. Add to that the fixation some pilots have to the magenta line and there is no doubt that SOME pilots are not well-practised in looking out or even worry about it.
Too often I have had close calls when another pilot has failed to follow the rules of the air and made the slightest attempt to alter course. As I don't trust anyone to do the right thing (except me!) I make sure I give other aircraft a wide berth, as far as possible.
It may be that they are flying on instruments in VFR conditions or be on autopilot. Despite what many say I doubt they are looking out as much as they should.
If only they started in gliding they might understand the need to keep a proper look-out....
