u/Utkozavr

PIE is usually reconstructed to have three series of stops: voiced, voiceless, and breathy. According to the Leiden version of the glottalic theory, at the Late PIE, those were (pre)glottalised, fortis, and lenis.  (Perhaps voicing wasn't a phonemic characteristic, though it could exist allophonically. Kinda like in modern Korean, I guess?)

Kortlandt provides quite a few arguments in favor of the glottalic theory here.

Kloekhorst's conclusion here.

Are there any arguments against this interpretation of the glottalic theory?