Audiolabyrinth, I too lament the direction you've outlined. The founders of the above mentioned companies have moved on, leaving the direction of their companies to profiteers'.
Like many things in life, fashion is cyclical. I imagine that when the economy improves we might see more big iron, though the future of big power might come more from Class D.
In the interim, smaller, lighter amps have the advantage of economy of scale (materials, case work, packaging, shipping, etc.) with corresponding higher profit margins. Smaller, lighter amps with the added feature(?) of adjustability (tube rolling) lends itself to hobbyists who like to tinker for the sake of it, and/or who are more likely to buy if it's more convenient to do so. To be honest, even as one who appreciates big iron, I don't look forward to the expense and inconvenience and shipping(!) of swapping out these heavy pieces.
Those that can afford such gear are often times now buying for multi-channel HT systems that makes big iron even more challenging to deal with.
I don't agree with the notion that there is a ceiling on the amount available power that can't be exceeded without compromising quality.