Gazoo,
I agree with your assessment as the bar is now in the 210 area.  In my league that I've bowled in the last 5 years that would seem to be the case.
the 2000-01 season there were 3 or 4 bowlers over the 200 mark when we had 22 teams, last year we had 3 bowlers over 210 with 16 teams. So, that bar is a little better than the top 10%.
 I think the problem comes in the next group, the people who are now in the 190-210 average group.  5 years ago, that group was 180-200, there were approx. 25 in that group out of 88 bowlers, about 30%, last year out of the 64 bowlers in league, in the 190-210 range, I would estimate that there were 30 in that group or about 40 or 45%.
This is the biggest reason you see the better bowlers complaining about the new tech in the balls. Today, you really don't need the physical ability to create optimum entry angles to carry strikes consistently.  Five years ago I carried 172 ave. while my accuracy has improved some, this last summer league I finished at 193, I don't believe that I am 2 strikes better per game than I was 5 years ago, but with the newer balls that I am using, I will get those 2 extra strikes per game.

the problem with just adding 10 pins is bowling is not scored linearly.  There is the law of diminishing returns in bowling so suggesting that "par bowling" should be +10 because the average is now 178 from 168 is faulty, by a small margin.

Without doing any math and taking a rough guess, I would say par by your standard should probably be around 207 or so, +/- 1.

In regards to bowling averages as they relate to the overall handicap a player has, why isn't it calculated like golf in that it' based on potential?  I understand an average should be the sum of all games divided by total games played, but for league handicap purposes, maybe a handicap calculated by potential would be more fair?

It just doesn't seem fair when a 150 average goes against a 210 average.  The 150 guy can easily sore pass their handicap for a game where as the 210 bowler has a much harder time.  Usually lower averages are an aggregate of terrible and great games where as the 210 average bowler is generally more consistent.

If we based it on potential then the 150 average bowler would probably be treated like a 165 average bowler and the 210 bowler would stay around the same.

From my paper experiments this makes it more fair in that since scoring is not linear and the 210 average bowler has a harder time going over average (because10 more pins on a 210 is much harder than 10 more pins on a 150..2 opens to convert a spare versus 4 or 5, for instance).

Also, usually someone around 150 is usually improving anyways and has the potential to have unbeatable games.

I should probably make this into a topic and discuss in more detail my intentions here.