My father is an EE, and has traditionally preferred solid state amplification. He's of the generation that led the migration in that direction as well as a devout objectivist.
However, over the past decade, he's once again embraced tubes, though not completely. He's had the benefit of seeing how things have evolved since the 1950s when he was coming up, and concluded that over the very long haul, the longevity of a tube amplifier eclipses that of solid state. Most surprising to me, he espouses tube rectification and the absence of negative feedback; with logical justification, of course. And, though one "has to always get back to the numbers", he feels the sonic benefits in certain regards also provides justification for tubes.