Because it won't work?
Well, it might work for PF30 where the cups sit outboard of the bb shell, but BB30 bearings usually don't sit flush and are slightly recessed. That tool will foul on the BB shell before the bearings are pressed against the circlips.
Sorry, I should have said it is to install a praxis adapter BB.
Might work OK then, assuming the threaded rod is narrow enough to go through the 24mm id bearings (looks like it is).
@gillies started
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Because it won't work?
Well, it might work for PF30 where the cups sit outboard of the bb shell, but BB30 bearings usually don't sit flush and are slightly recessed. That tool will foul on the BB shell before the bearings are pressed against the circlips.