This is all completely subjective and depends on what the user is used to. That being said, try rendering a graphic on a Quad G5 and then on a single G3, you will see a substantial difference and understand what they mean by "slow". Each user is different, you and lil may be satisfied with what your machines do for you, others would/might not be and desire more. Either way, there is no right or wrong answer or attitude here, it is all simply based on the desire of the user.
People expect results for their money, especially when it comes to computers, but the former Intel Ad campaign convinced millions of people (like the OP apparently) that speed in Mhz or Ghz was the most important thing in the world when buying a computer. Understanding why that isn't true is something that millions of folks can't, don't or won't understand, perhaps ever.