I use my laptop in a professional capacity and weight is a huge factor for me. I carry my laptop everywhere.

Incremental yearly changes in weight have generally not been that impressive but in aggregate the difference is huge. Go pick up a 10-year-old laptop and you'll probably agree.

> Structural engineering: It's half as thin. If you know mechanics, you'd need a material double as tough in order to make up for the loss in structural stability.

I'm no mechanical engineer, but I don't believe that's correct. There are a number of factors that impact the structural stability of an item. The internal structure has a huge impact, which is why I-beams exist.

It's also not as if the space saved is the result of just milling out half of the original aluminum. The actual metal case is probably the same thickness or close.

So a lightweight/reasonable performance Macbook line and a little heavier/high performance Macbook Pro makes so much more sense.

Forever people have said that they would prefer a heavier laptop with a bigger battery and for better or worse, companies have generally ignored that. I don't think it's really a "pro" issue either way.

But basically, for a laptop to be half the thickness and equivalently strong it will need the structure to be twice as heavy, as the skins and webbing need to be twice as thick. That leaves even less room for battery, quiet fans and replaceable components, a high price to pay for something which is labeled "Pro".

It's far from clear that this is 'simple'.