This is hardly "where sedevacantism leads".
Why not? If they feel compelled to judge the entire hierarchy to be formal heretics and apostates that have abdicated their respective offices, why would they not logically respond by electing another Pope? If justice demands the former, why not the latter? Do they not really care about the common good of the Church? Are they content with deposing clerics leaving the Church headless and bodiless? Since they alone are the ones who see the true nature of the problem and are objectively the sum total of the Catholic Church, why would not the self-same Catholic Church elect duly appointed leaders? This man is doing the Catholic Church a great service by attempting to finally bring this crisis to an end!