Pat,
It may be that more bunkers have been removed than added over the years (as per my post on Joe Dey at The Creek), but to conclude that it was done to make the course play easier so that poorer players could compete with better players requires evidence - recollections of those involved, detailed board minutes or some such.
Again, it may be that a course is changed to make it easier for poorer players, but your question cannot be answered without knowing why this was done. At a course I am very familiar with, in the early 1960s greenside bunkers, which had generally been placed a bit away from greens (10-20 yards), were brought much closer to them. The person who did this stated that this would make the course play more difficult for the better player who tried to get the ball close to the hole and had to flirt with them, but play easier for the higher handicappers because they didn't hit many greens, and would not get in as much trouble if they were well short of greens. However, this was done at the behest of better players who wanted the challenge rather than by poorer players who wanted to win more money in weekend scotch games.
We have also seen "wild" greens and other features from classic courses posted here; do we know, for instance, that the 2 or 20 hole at Forsgate was taken out of play, or other features destroyed at the behest of weaker players because they were too difficult; or were some removed because better players thought they were unfair? I suspect some of both, but I won't buy the idea that the latter never happened.
Also, you seem to indicate in your reply to Rich Goodale's post that golfers will always attempt to have the features that influence their game for the worse taken out. I don't know that that was true 50 years ago, as you suppose in the amendment to your question, but these days it seems that the emphasis is to provide more challenge to better players, something that is antithetical to your claim (better players would want the stuff that troubles them wiped out too). Butler National isn't being torn up because it was too hard.
At another course contemplating renovations that I am familiar with, the idea is again to make the bunkers more difficult, add tees that in fact would destroy the strategy of the holes, and do other things to make the course harder. Maybe it's just a product of the midwest.
You are correct that I am less familiar with changes made decades ago. I would be interested in a few examples of courses made easier specifically because weaker players wanted to be able to better compete with better players. Thanks!
Jeff Goldman