I thoroughly disagree that just because someone else doesn't understand the value of something, that something loses value. If I hand my baby a gold coin and all it knows to do with it is stick it in its mouth, has the coin lost any value thereby?
It has no value to the 'baby', the receiver of the coin.
Do you consider speaking in 'tongues' a mystical experience? If so, of what value is there when words spoken are meaningless to anyone, including the one speaking. Yet Moses, Prophets and Jesus were quite successful,