Yep, the sharp edges suck. Numerous people, including myself have emailed Apple about it over the years.
They still exist. It's incomprehensible why they would put a product out with this design flaw.
Sure, sitting at a desk or table with you hands in "correct typing position" your forearms should not come in contact with the sharp edges.
BUT, the is a notebook computer, it gets used in all kinds of places, desk, tables of various heights, couch, plane, recliner, bed ... Sometimes in those cases the typing position isn't ideal and your forearms therefore come in contact with the sharp edges.
It wouldn't cost a penny to have the edges on the MBP's and MBA's slighted rounded.
I laugh when people here say the edges aren't sharp. They ARE and if any of the naysayers rest their forearm on the edge of their Mac notebook for a moment you'll see a very distinct line engrained in your skin.
Happens to me mostly when I'm typing in my recliner or on a plane. It's uncomfortable an unnecessary. That's why I use the Air, less prone to come in contact with the edge due to thin/tappered design.
The rMBP has the sharp edge too, it's the first thing I looked for. All this redesign and they couldn't finally round the edges a little. Wow. It's a head shaker.