Why adjust surface? Why maintain equipment?
Because you care about reaction and carry? That's why I do it...
Because bowling balls aren't cheap and we would like to get the most out of them as possible? Nah, bad reason. Because we all don't bowl on exactly the same conditions? Nah, bad reason. How about because we care about scores? Horrible reason!
No manufacturer will ever find the "magic" surface that suits everyone's conditions. The factory finish is a starting point, nothing more or less...
On the easiest of conditions you will be able to get away with doing less routine maintenance (for awhile, anyway), but eventually most of today's bowling balls need to be maintained to some extent or you're throwing away pins every game. You decide.
I can't even count the hundreds of bowling balls that were brought into the shop over the past 12 years or so, that I helped restore reaction and carry and the bowler's enjoyment level was restored.
Face it, what do most bowlers do when their ball loses reaction? They try to FORCE reaction, which hurts their consistency, or eventually they want something new. With some routine maintenance many of today's balls can be very good for hundreds of games. Do you ever change the oil or tires on your car? Of course, because you want it to last longer...