There's a serious ethical problem with allocating scarce healthcare resources, particularly those in theatre to ideas that have no evidence of being worth trying. There's also significant risk from blood infusions being done improperly, including infecting more healthcare workers who then may end up in close proximity to ebola patients even longer.
If this were being done in a 3rd party country - e.g. the UK or the US or spain, where a blood transfusion or two, even under the most stringent of containment procedures is a very marginal cost I'd say sure, you may as well try. But when you're talking about potentially thousands of infusions on thousands of patients in poor countries, in facilities that are suffering shortages of staff because staff keep dying, and suffering in sanitation, and well... it may not be a great idea.
If you save one patient with a blood transfusion but kill 2 others who accidentally get infected you're not really doing a good thing.