Whether your claim is true or not, there’s more to a product than the underlying technology. Frankly, this line of discussion reads as sour grapes and reflects poorly on the Linode team.
Back when I was just hacking about on some SaaS ideas I looked into both Linode and DO. The positioning of both seemed quite separate to me, and DO "felt" more like the product I should be using.
Whether or not the tech was different, or that feeling was justified by anything other than an initial veneer is well up for debate - but entirely agree, they're discreet products, and this doesn't really reflect well on Linode.
I'm not arguing if DO was a clone or not, but saying that "you could use Linode/Slicehost documentation because DO was a clone" is a bit of a stretch.