Allthough I agree lightweight is preferable, in my opinion it is unreal to expect heavy duty gear without weight. These keyboards are not produced in large numbers like cars, so any weight reduction will most likely cause less durability. ( look at you all complaining about the bad keys of the psr 2000
)
The only way to produce light weight/heavy duty is the use of new composit materials which would require very large investments and probably double the price of the boards
Now for the pro users transporting a lot by themselves (mmm where are the times of roadies..
) I understand and agree any weight reduction is great, but what happens with your keyboard after a year of heavy duty usage? You sell it! In fact you sell it before it is garbage..! These boards have another life with the second and maybe third user... The producers know this and also know that a starter will probably buy a new board from the same brand if it is durable.
My personal opinion is that it has improved a lot.
(remember.. carrying hammonds(cut in two pieces) and leslie's , heavy fenders etc...and I do hate it still)