It looks like the article may have updated this sentence. It now reads as:
> Mostly because people didn't believe that it was possible to exploit the retpoline limitations, it was somehow logical -but risky- to refuse to implement a mitigation that would slow you down.
In the version you quoted, I'd call it "clumsy" due to a lack of logical comparison from the left- and right-operands of "versus". I could understand what the author was getting at, however.
I'm not a native speaker, but is this an acceptable written English? The part starting with "versus" seems out of place.