Dean,
I do agree with you as I don't care what other people use to determine their yardage.
I guess I'm semi old fashioned as I do like a visible (vertical's helpful)150 marker such as a stone,post, or plate in the fairway as a general reference. The nice thing about something vertical is if Im more than 150 out I can be judging the distance AS I WALK UP to my ball and AM READY TO GO when I get there.
Conversely, if I'm inside the 150 I can easily pace it off or if I'm distracted looking for another's ball or something, I can look back and be ready immediately.
Most people these days won't do vertical markers because the golf world (and yes the GCA world) has gotten WAY TOO FOCUSED on form over substance and the type of signs, trash cans (holes in the ground for rakes!)no hole signs,edges on bunkers etc.
Go to any Uk/Irish course and you'll see 150's (often colored 100 and 200 plates) as well.
In my opinion we've gotten way too focused on what people think and in an effort to discreetly put yardages on certain sprinklers (but not all) we've forced the yardage dependent player to run around finding plates or use a mechanical device,and denied him the chance to perhaps learn to estimate what 50 yards look like and use something simple like a 150 to supplement/confirm his judgement.
Of course we could put nothing out and have him eyeball it-that's ok too but as Adrian stated that's commercial disaster