You argued above that nihilism allows one to form a positive doctrine for re-evaluate of ones values and that the end of tradition that produces the possibility of new things to come. However, there is no reason to think the goals of progress and improving our value system and cannot be achieved from a framework of theism. With this in mind why choose a philosophical belief that is potentially unhealthy and detrimental to the progress we have made so far?
Metaphysics is ontology and epistemology, not morality. Biology has nothing to do with truth, sequoias live for hundreds of years and learn nothing. Anthropological arguments are the only pertinent, but I'd say we're already overpopulated given our capability for wealth distribution.
I think they will be achieved from a framework of theism, but in a slow way, that will leave behind piece by piece the spiritualism from theism, until it is reduced to the pure belief of transcendent perfection without content. That kind of theism would be compatible with nihilism and the two could coexists as mutually agnostic. The problem is that traditional theism brings spiritualism, and that spiritualism is just a more primitive type of thought, and that its bad when applied to knowledge, or morality. For example its hard to understand and artificially reconstruct the mind, if people think its an eternal substance completely separate from matter.
Basically, I don't really care what anyone believes, as long as it doesn't determine knowledge, but because spiritualism practically always does, I'm against it.
Nihilnegativum I have had time to consider your argument in greater depth. My response to you is that nihilism is incompatible with your goal of advancing knowledge. The arguments to show this are extensive and complex and I do not want to post them all here so I will link to them.
The Foundations of Contentionism:Cycles of ContentionThe Rise of KnowledgeEntropy is InformationThe Math of Optimal FitnessThe Limits of ScienceReligion and ProgressThe Nature of FreedomMorality and SinKnowledge, Entropy and FreedomThis is a complex topic and I do not necessarily expect you to read all of that but I think you would find the logic interesting. In the 9 links above I (and others) describe the relationship between knowledge, freedom, entropy, and progress. Once this relationship is understood it follows that nihilism undermines the fundamental drivers of knowledge creation. Thus nihilism does not advance knowledge it destroys it.
A very brief and incomplete summary of the argument for those without the time to read the links follows: (Going from top to bottom of the above links)
The argument starts from the premise that empiric knowledge exists or at least appears to exist. It goes on to define information in the context of entropy and knowledge in the context of information. It further argues that information (degrees-of-freedom) cannot be infinite or it would not converge to become knowledge. The nature of empiric knowledge as necessarily incomplete is reviewed as is the requirement for apriori. The apriori assumption of theism is explored and its functional role as the primary driver of knowledge growth. The nature of freedom is explored and its role as the functional intermediary between theism and knowledge growth. Consequences of the rejection of theism are reviewed. Sin is discussed in the context of wrong judgment or noise. The argument concludes with observation that ethical monotheism appears to be a the minimum constraint needed to ensure convergence of information to empiric knowledge. Thus the apriori rejection of theism (nihilism) is incompatible with the growth of empiric knowledge over time.