Technically this is true in some respects (objective measurements) but it's not borne out by subjective listening IMO, particularly in audio amplification and in driving electrostatic headphones specifically.
In fact scientists have now realised that the vacuum tube has much to offer and are actively developing combined solid state and vacuum tube devices. http://www.gizmag.com/nasa-vacuum-channel-transistor/22626/
"NASA and the National Nanofab Center in South Korea are working on a miniaturized "vacuum channel transistor" - a best-of-both-worlds device that could find application in space and high-radiation environments.
Vacuum tubes, or thermionic valves, have almost disappeared from our day-to-day life, save for some purist sound rigs and high-power radio base stations. Their replacement - solid-state transistors - are easier to manufacture, cheaper, lighter, last longer, and consume much less power. Valves, on the other hand, are more robust in high-temperature and high-radiation environments and yield a higher frequency/power output than standard transistors.
NASA/Nanofab researchers are developing a device the combines the best aspects from both vacuum tubes and solid-state transistors. Their prototype "vacuum channel transistor" is only 150 nanometers in size, can be manufactured cheaply using standard silicon semiconductor processing, can operate at high speeds even in hostile environments, and could consume just as much power as a standard transistor."
Tube amps are flawed based on limits in technology just like analogue recording and storage were. Digital and solid state are in another league . It's a fact. That's not up for discussion. What is and needs to be considered is personal preference. That can't be accounted for so there is no point in arguing about it.