Because dishonest people insist on conflation evolution with theories on the origin of life. No one asserts that we understand the origin of life, and no intellectually honest person asserts that this is relevant to understanding ongoing processes that we can observe.
The argument that evolution requires inference is just stupid and ignorant. Everything in science involves inference. Do you believe Newton's raw data conforms to his equations?
"The argument that evolution requires inference is just stupid and ignorant."
I must have missed where this argument was made.