Which sport do you think should be kicked out for Bowling?
BMX? Well that's part of cycling, so every bike event would have to go.
Sync Swimming? That's under Aquatics, so say goodbye to all swimming events.
Trampoline? There goes all gymnastic events.
There is only room for 28 sports on the IOC Summer Olympics Program.
Aquatics, Archery, Athletics, Badminton, Baseball, Basketball, Boxing, Canoe / kayak, Cycling, Equestrian, Fencing, Football, Gymnastics, Handball, Hockey, Judo, Modern pentathlon, Rowing, Sailing, Shooting, Softball, Table tennis, Taekwondo, Tennis, Triathlon, Volleyball, Weightlifting, Wrestling.
Lucky enough, baseball & softball have been dropped from the 2012 program. There was a vote to elect 2 new sports to replace them, but they couldn't agree so there will only be 26 sports for the next Olympics.
This means that now is the best chance Bowling has of getting into the Olympics, but in order to get there somebody in the IOC needs be be singing the praises of Bowling louder than the people who want Golf, Squash, Rugby, Karate, Roller Sports there as well as those who want Baseball and Softball back on the list.
In the end, the sport isn't what is keeping Bowling off the program. It's not the oil patterns or ball designs or "luck" factor. It is the fact that at the top level of the IOC, there are few bowling fans.