. Too much invested (can't be wrong). Image (gotta be the 'right' tube amp too), If SS doesn't sound like a tube then .. so what? Does a tube amp sound like SS? Do you want to be the player everyone says "sounds just like so and so" or instead, to get to be a famous player you need to hear "you're an awesome player, what a great tone" and that does not necessarily require tubes. The downfall of tubes, and why SS is making more inroads: -Tubes are called big iron for a reason, big and heavy -fragile -high maintenance, gotta replace tubes every year and re-cap the chassis every decade (except bedroom players can go longer) -high initial cost -- actually a more simple circuit than ss, but priced for a bigger profit margin What really kills tube amp use is the aging player population just doesn't want to carry that big heavy anchor around. That will continue. The amp companies who survive will build acceptable lightweight solid state amps 'that get that sound' .