Tim Draper probably understands, privately, that Theranos is an unrecoverable loss. Privately, he has probably learned a lesson about doing better due diligence going forward. Publicly, he is doing what he thinks will benefit him the most: he is signalling to all prospective future investments, that, "If you take my money, I will stand by you through thick and thin." Some future founders might be turned off by this, but some will probably see it as invaluable.