There are clearly situations where an old Mac is still an excellent thing to give to somebody, but they are few and far between.

• There is first of all the collector/ tinkerer who will genuinely enjoy the thing (and most likely join the 68kmla).
   
  Three years ago, I gave a PowerBook 540c to a mentally handicapped adult, installed At Ease with some simple games, and it is still being used more or less daily. He has some friends like himself who have asked where to buy the machine and the games, because of course they can't find anything like them in the shops. Where else could you find such ease of use than on an old Mac, prior to OSX?
   
  Just today at work I used Acrobat 5 in System 9 on a Pismo to do something that, as far as I know, otherwise could not have been done without actually buying a current version of Acrobat; the price I paid for version 5 at a Garage Sale sure beats the price of it new. Thus the Pismo+OS9.2+Acrobat 5 handily outperformed the high-end Intel iMac on my office desk for usefulness.

The trouble is that kids and families are generally not aware of such niche uses, haven't the room for a machine that can do them, or have the standard prejudice that new technology is always best. That's what the culture teaches them. But most of all, they want the web (my teen-aged kids, for example, don't know their friends' phone numbers, such is the ubiquity of FaceBook), and that is the real limiting factor.