Maybe we should look at your question from the opposite side. What is the validity of assumed spirituality in absence of consensual reality? In many respects, deep spirituality is integrally linked to the depth of reality of one's life (my opinion at least).
I might disagree... although I know what you are saying. Much of what has been considered spirituality of great depth requires going into some alternate paradigm of perception of reality. This has often contradicted "consensual reality". This has always been a reality that contradicts the fundamental way ordinary folks perceive their reality. This is what has traditionally made it difficult to decide if someone's spirituality is genuine or he or she is a charlatan.
In Aikido it is equally difficult in that we are willing to accept that the art is a mix of the spiritual and the technical. The question is... does great technique yield deep spirituality? I think it is apparent to all of us that this is not a necessary result. Or does spiritual insight yield great technique. I think we can readily see the disconnect there.
If you look at someone like the Founder, he was rather other worldly in both respects. He had a very different world paradigm from that in which most folks function. He also had a technical level of ability that seemed other worldly to many. I do think that what makes Aikido truly Aikido is that if ones insight is valid, he or she can manifest that insight on the mat technically. That's the bottom line. Ones "other worldly" spirituality and technique needs to function with people whose reality is firmly anchored in the ordinary mundane world. O-Sensei could walk his talk. Most of the deshi could walk their talk on some level. Most of our contemporary Aikido folks cannot do so on the level that was once considered important.