It's a shame and at the same time a blessing.
A shame that certain balls cannot be used longer without maintenance. I know, I have a great
deal of confidence in one of my balls. It lasts a long time with routine cleaning, but twice in a year and a half, I have had it resurfaced. I required about 10 games to get back to my comfort level with it as the ball finish is not just right until then.
On the other hand, it is a good thing to have another ball to use when the conditions dictate. A pearl versus a solid cover will react very differently and there are instances where you have to use one over the other.
The ball companies have developed balls that are different, and conditioned the bowlers to have and carry multiple balls.
Like the philosophy of a spare ball. Not only does it help to roll straight with it. But, the thought now is that it also saves your strike ball from overuse. I guess, in theory, my strike ball should last twice as long??????