ये त्वेतदभ्यसूयन्तो नानुतिष्ठन्ति मे मतम्।सर्वज्ञानविमूढांस्तान्विद्धि नष्टानचेतसः॥
ye tvetad abhyasūyanto nānutiṣṭhanti me matamsarva-jñāna-vimūḍhāns tān viddhi naṣṭān acetasaḥ
Word by word
The verse says
But those who pick at this and do not follow it - know them to be lost, confused about everything, out of their senses.
In plain words
The other half, and it is unusually harsh.
Naṣṭān - ruined, lost. Acetasaḥ - without discernment.
This is one of the sharpest sentences Krishna delivers in the whole book, and it comes immediately after a verse about not disturbing people.
Where you've felt this · in community
Your colleague's whole contribution to every planning meeting is finding the flaw in each proposal. Over a year he is right most of the time. Over the same year he has built nothing, and nobody asks him to start anything.
Going deeper
The harshness deserves an honest look rather than an explanation that files it away.
Read at full strength, this is the text condemning those who reject it, which is the least attractive move any scripture makes and the Gita is not exempt.
Two things are worth holding alongside it. First, the target named is abhyasūyantaḥ - those carping - not those who disagree, doubt, or fail. That is a narrower category, and the distinction is in the Sanskrit rather than imported.
Second, the verse sits three lines after a firm instruction not to unsettle people who do not understand. Krishna is describing an outcome, not authorising anyone to enforce it.
It is also worth noticing what naṣṭān and acetasaḥ actually say. Not wicked. Lost, and lacking discernment. It stays inside the book's steady framing of the problem as a disorder of seeing rather than a crime.
A reader is entitled to find this verse unpleasant. It is more useful to know that than to be handed a softened rendering.