"The adjustable webbing suspension is basically a cinch-buckle type suspension. If you choose this suspension, you’ll get 14’ of webbing per end. Each piece has a loop sewn into one end. You’ll place carabiners (sold separately in the accessories section) in these loops so you can simply take the webbing around the tree and clip back onto itself. All length adjustments are done by adjusting the webbing at the cinch buckle. This is by far the most quick and convenient type of suspension, and by far the most popular option."
Yes, you can 'use it as shipped' but that would be going beyond what the set up instructions tells you to do, and could result in you screwing up the suspension. I wasn't insinuating that he should be including insulation or the like I was refering to the actual hammock setup, but biners are cheap (even dutchware stuff is cheap) and adding $5-$10 to the cost of the hammock and INCLUDING them just seems like a good approach to me, especially when the instructions state to use carabiners and doesn't say how to use it without them. I purchased a dutch suspension with mine so it isn't a problem for me personally, but I can see how it could be. If not include them, at least make it more apparent in more places that you will be needing them, not drilled down into the hammock suspension area, where someone might not look when going to buy a hammock.