Sorry for being late to this party
This piece was written from the perspective of a player and was motivated as an exploration of why playing through a DAW felt 'wrong'. The effect really is easy to experience in this context and it matters in that the player is taken out of the moment / flow which (at least) impacts their experience and can change the performance.
Critically, the effect is random, variable, and not musically related. Fixed delays are regularly adapted to (a few have been mentioned above but they are not really relevant to this discussion). Regular, musical changes can be intentional (for example, swinging beats) but just randomly clustering notes is problematic and clearly disturbs, for example, fast arps (emulating strumming, for example).
I happen to play the same instrument as the author. It is intended for live performance (not to say one cant use it otherwise). It happens to have its own music production environment which is extremely low latency and high bandwidth and has native instruments or can host AU/VSTs. One result is that playing it is much more like playing 'real' instruments (like, say, something fretless or a reed instrument) where the player interacts in real time with the instrument to bring out a particular note and tone. This requires very immediate feedback and fine resolution in control signals (I happen to think this is one reason people like CV over midi as well). When one moves out of the native environment it, impacts like the one in the article can be very clear. Many people who lay down tracks with it record audio (vs MIDI) for the reasons above.