Because exceptions are designed for exceptional circumstances, there is little incentive for JVM implementors to make them as fast as explicit tests.
Kind of a spurious statement. JVMs (standard and competitors) have evolved a long time, and a ton of effort has gone into optimizing all aspects, including making exceptions as fast as possible.
That's not to say that Exceptions aren't as fast as explicit tests— they're more inherently more costly (e.g., have to collect the stack trace, instantiate the exception, be treated as the less likely code path for predictive optimizations, etc.)— but it's not because there's lack of incentive.
