Evolution takes many slings and arrrows because it doesn't explain the origins of life. Yet I agree somewhat with our critics: Biology should not avoid the topic, but is in a good position to pursue it (for example: the Miller-Urey demonstration in 1953).
Abiogenesis is probably best left to the chemists.
Even in biology, though, it's really not a part of evolution.
There's a difference between *evolution*, and biology in general. Abiogenesis is a valid topic in biology, but it's still a topic independent of evolution, pretty much by definition. Biological evolution deals with the process of replication -- no replication, no evolution. So whatever the process(es) might be which gave rise to the first replicating thing, they didn't involve evolutionary processes, because being "pre-replication", they were "pre-evolution" as well.