A fair point, but of course you have to go back to 1917 to find the last White Sox championship before '05. So it does seem as if the odds are still skewed against.
Besides, while I do find this theory intriguing, I’m not entirely sold on the weight of its significance. The Cubs won six pennants in the '10s, '20s, and '30s, so they managed to do pretty well at Wrigley for a while. It may be somewhat statistically odd that they didn’t win any World Series in that time, but you could attribute it to plain bad luck, or the dominance of the AL during that era (AL teams won 21 of 30 WS in those decades).
But I’d probably point to poor ownership as the major factor in the drought. Phil Wrigley inherited the team from his father in 1939 and was known for throwing nickels around like manhole covers. His tightwaddery essentially doomed the team to mediocrity or worse for the next 4 decades. He died, and the family sold to the Tribune Company, which essentially treated the Cubs as a corporate afterthought. They showed some improvement in the '80s, but the budget was still tight and management had no real direction.
Under the current ownership and management, it remains to be seen if things will change. Ricketts and Epstein seem to have the right philosophy and are starting to put some promising building blocks in place… but as John Hiatt said, it’s a Slow Turnin’.