Please describe what a testable hypothesis is according to you. You seem to believe that "evolutionism" requires that abiogenesis happened. Since I don't know what "evolutionism" includes, since that word is not in any dictionary or science book, I cannot say that you are wrong. However, the Theory of Evolution does not require abiogenesis.

Be that as it may, please check out:
http://en.wikipedia.org/wiki/Origin_of_life

You will find a number of hypotheses on how life may have formed within the physical laws that govern our universe. The emphasis is on "may". Even if eventual experimentation shows that every one of those methods can form life, we still would not know which one it was, if it was any of those because we weren't there. Showing that a particular hypothesis for abiogenesis is possible, only increases support for the idea that abiogenesis did happen, somehow.

If by untestable you mean can we test that a particular method of abiogenesis occurred 3.5 billion years ago, then it is untestable. However the method is not untestable.
The questions concerning abiogenesis are along the lines of..."Could iron sulfides have formed some of the energy transfer pathways necessary to initiate a form of lifelike compounds? Tests can be done to see if that is a possibility. So the methods that are hypothesized can be tested and can fail those tests (falsifiable).