In plain words
Even a person of knowledge acts according to one's own nature; all beings follow their nature. What will mere suppression accomplish?
Word for word
Even a person of knowledge acts in keeping with his own prakṛti; beings follow prakṛti; what will restraint accomplish?
The commentators
Bhagavadgītābhāṣyam
कस्मात् पुनः कारणात् त्वदीयं मतं नानुतिष्ठन्ति, परधर्मान् अनुतिष्ठन्ति, स्वधर्मं च नानुवर्तन्ते, त्वत्प्रतिकूलाः कथं न बिभ्यति त्वच्छासनातिक्रमदोषात् ? तत्राह —
सदृशम् अनुरूपं चेष्टते चेष्टां करोति | कस्य ? स्वस्याः स्वकीयायाः प्रकृतेः । प्रकृतिर्नाम पूर्वकृतधर्माधर्मादिसंस्कारः वर्तमानजन्मादौ अभिव्यक्तः ; सा प्रकृतिः । तस्याः सदृशमेव सर्वो जन्तुः ज्ञानवानपि चेष्टते, किं पुनर्मूर्खः । तस्मात् प्रकृतिं यान्ति अनुगच्छन्ति भूतानि प्राणिनः । निग्रहः निषेधरूपः किं करिष्यति मम वा अन्यस्य वा ॥ ३३ ॥
In plain words
Then why is it that people do not live by your teaching — why do they take up duties that belong to others and abandon the duty that is their own? Standing against you like this, how is it that they feel no fear of the guilt of breaking your command? To this he replies —
Everyone acts in a way that matches their own nature. Whose nature? Their very own — nature here simply means the imprint left by all the good and bad they've done before, showing itself the moment this life begins. Every creature acts exactly according to that imprint, even someone with knowledge. So what chance does a fool have of doing otherwise? That's why every living being simply follows its own nature. Trying to force it into line from outside — what could that possibly accomplish, for me or for anyone else?
Close to the Sanskrit
But from what cause do they not practise your teaching, do practise the duties of others, and do not keep to their own duty; being opposed to you, how do they not fear the fault of transgressing your command? To that he says —
In accordance with, conformable to, one behaves, performs behavior. Of what? Of one's own, of one's own, nature. Nature, namely, is the latent impression formed by merit, demerit, and the like performed in a previous [birth], manifested at the beginning of the present birth; that is nature. In accordance with, precisely, that, every creature, even one possessing knowledge, behaves; what then of the fool? Therefore, beings, living creatures, go toward, follow after, nature. Restraint, in the form of prohibition, what will it accomplish, of me or of another?