O scorcher of foes (Arjuna), those humans who are inattentive and averse to the pursuit of yoga-sādhanā, unable to reach Me (the Supreme), return to the worldly path of recurring deaths.
Krishna is firm to make Arjuna and others discreet about the need to ascend to the transcendental level. Krishna reiterates this point.
To be indifferent to yoga-sādhanā is to remain trapped in ephemerality, disregarding the place and purpose of human life as set forth clearly in Vedas, especially the Upanishads. The sole mission of Upanishads is to enlighten seekers. Upanishadic exhortations will enhance viveka (discrimination), making one accept the indispensability of the knowledge-path leading to the Supreme.
Inattention and lack of viveka will result in missing the greatness and blissfulness of the Self, which Upanishads expose vociferously. As a result, one will remain enmeshed in the transitory gains here and hereafter. The misplaced addiction to rituals will continue, and consequently one will remain a victim to the cycle of births and deaths.