I agree with you, though, I believe the opposite can be true also.
When I started bowling as a junior with rock hard 16lb bowling balls (from my grandfather when he bowled in the 60's) - Think they where made from pure rock (think Flintstones!)
. The lane conditions and balls where conducive to the same shot making. If you put the ball in the same spot the same way it will do the same thing for 20 games!
With the ball technology and high friction, a heavy oil or long oil condition can make some of the high tech balls track 'similar' to the above situation. The oil does not let the ball traction as much until it reaches the dry and the stored energy forces the ball to make a consistent arch to the pocket.
Then come to a league where oil is placed sparsely and with no apparent forethought of pattern and watch the ball sail coast to coast, move the little oil that was in that spot forcing the bowler to move after 2 frame (and repeat). On some 'house' conditions it is easier just to go to my plastics and have fun with it. On these conditions, usually I score higher after going to plastic anyway. Hmmmm.
I know everyone shouts now, the ball is not the right ball for the condition. When you can only afford one bowling ball a year you just have to make do I suppose.
Essentially what I am trying to say is that both environment (before 1990 and after) have their own idiosyncrasies and challenges. Who is to say which is better. Take Belmo back in time and I am sure he will be, back then, where he is now. On the PBA tour and Australians finest bowler for the time.
My $0.05
Cheers.