I got myself a 2DS and have defended it ever since. It was the most comfortable console in the 3DS family at the time (Now I have a New 3DS XL that is more comfortable though) and it cost me one third, or less, than what the 3DS would have costed me, even if I got the 3DS at a good deal.
It filled its function, in a great manner, and while I kinda do get the dislike for it (It really looks horribly uncomfortable), most people who hate it doesn't seem to have tried it.
I think the hate is also in the same manner as those who hate on "casual gamers" as not being "real gamers", because you buy a cheaper version of the console.