If direct path is preferred in the speaker by most, why the acceptance of a glass army in one's amp/preamp?Not sure what is meant by 'direct path'... But if you need a lot of power, you might need a lot of tubes to make that power. If so, they'll be in parallel, which means the signal is fed to all of them and they all work in tandem to make that power. In that particular case, the signal path complexity is the same whether one power tube is used or 20.
We have a good number of power tubes in our amps because the power tubes, which are triodes, don't make a lot of power. But those amps only have one gain stage in the entire amp! That's about as direct as you can get.