It may not be wrong for the chord, but as I like to say , context matters.
If I'm grooving along on a Latin root-5 bass line, throwing in a root-flat 5 feels 'dissonant' against the groove (even if it's harmonically correct.) I can't play a perfect 5th because that would be incorrect. So I tend to go for the consonant sounding octave.
In my experience, a m7b5 is not a chord most songs linger on and explore. They are almost always transition chords of some kind, either moving around the cycle or sliding a half step into something more stable. So I tend to place more weight on where the chord is going than what the isolated harmonic implications of m7b5.
Perhaps I'm thinking of what the groove wants rather than what the theory wants.
Alternatively, I'm rationalizing a lazy imagination.