What flaws do you see with the arduino? Answered
What flaws do you see with the arduino and its "universe" (shields, modules, knockoffs, software &c)?
Although there are some that are quite apparent, such as the bizzare pin spacing, I'm sure there are some smaller issues that kept quiet.
I have nothing against the arduino, I think it's a wonderful little guy that's doing awesome things, and I'm really thankful it exists.