First off, I would like to know what speaker claims 1000 watts power handling. You are talking massive amount of heat to deal with there. Just curious.
I believe Crown suggests having twice the amplifier power as your continuous speaker rating, or thereabouts. Their reasoning being that peaks lasting for short amounts of time can be handled by your speakers, and you don't want to go into clipping.
You mentioned that some amps have low power, and yes, some do. Tube amps and many integrated amps will have 50 watts or less per channel power.
It all depends on the goal of the amp maker. Some amp makers go for amp stability into lower impedance loads, and trade off 8 ohm power output for that. Tube amps by their nature are low powered.
Nothing wrong with this. Efficient speakers, and "reasonable" listening levels in average sized rooms require little power to operate.
Home theaters supporting THX reference level peaks and deaf rock music fans need more power.
There's a law of diminishing returns for amp power. Double 100 watts to 200 watts, and all you get is 3 dB more SPL. Double 200 to 400 and you get another 3 dB.
Also note that you can only draw so much power from a power outlet. And there's articles on how increasing power to a speaker starts to run into some physical limitations so that you don't get the power you think you are getting.
All of this leads me to believe that 200 watts / channel is the a reasonable amount to ask for. There's also a point where you SHOULD consider your hearing! More than 85 dB continuous is bad for you, and I am a case study in this. I have hearing damage, and ringing in my ears. So don't be me, ok?