Is it too much to ask....

Power gives some idea, but it is pretty much useless specification without knowing how it was measured. My amp, for instance, has module rated at 200W/4ohm but only 55W according to FTC measurement (that requires 1 hour preheat). It is possible for the lower continuous power amp to be actually louder. Music power delivered to speakers is only a few percent of peak power (unless anybody listens to sinewaves). What about distortions? Bel Canto makes the same amp as Rowland 102 (same B&O module) with 300W rating since they specify it at 10% distortions. In addition overdriving some amps is painful (odd harmonics) while other amps (including mine) have soft clipping. There is also not that much difference when power doubles (only 22% of perceived loudness). Perhaps it would be better to know peak power and max current but most often it is not available.

while I can see the OP point, I also tend to agree with Viridian

If I am buying an amp here, i don't need to know Specs--I am into this hobby so I will get the information myself which I feel is critical.

If I were selling locally on Craigslist, people want to know Specs----like when I was selling my Linear Power car amp which is rated at 75 watts for $300 and someone let me know they could buy a 2000 watt amp at the flea market new for $69

Listing basic pertinent specs speeds up a possible sale. A amp's current may indeed be more telling than watts when it comes to drive and quality. But best to list something. Inquiring minds can take it from there.

Pictures, front and back of the unit go along way.

I don't think it is necessary to list all the specs but if you are selling an amp the least you can do is state the power rating in the ad. Even so I think most potential buyers will google the amp to see if the ad is accurate.