ये त्वेतदभ्यसूयन्तो नानुतिष्ठन्ति मे मतम्। सर्वज्ञानविमूढांस्तान्विद्धि नष्टानचेतसः ॥

ye tvetad abhyasūyanto nānutiṣhṭhanti me matam sarva-jñāna-vimūḍhāns tān viddhi naṣhṭān achetasaḥ

Who carp at My teaching and act not thereon, senseless, deluded in all knowledge, know thou these mindless ones as fated to be destroyed.

In plain words: Krishna says people who mock his teaching and do not follow it are confused and lack understanding. He warns that they are headed for ruin.