Two thoughts on this:
1. The title of the thread is "Training of Beginner Bodhisattvas", but is this cited statement from the text viz "beginner" Bodhisattvas? This is an important question.
2. The answer itself may be found in the text, where I've highlighted a key point:
Astus wrote:"One should speak like this – do not give up your passion, do not fight your aversion, do not clear away your bewilderment, do not liberate yourself from your body , practise the bad things , do not hold back your views, do not be conscious of the bonds [to the worldly things], grasp for the parts of the personality (skandha), amass the spheres of sense-perception, move about among the fields of sense-perception (āyatana), do not leave the stage of fools, frequent the bad (akuśala), give up the good (kuśala), do not think of the Buddha, do not reflect on religious teachings (dharma), do not give offerings to the congregation of monks, do not take the training (śikṣā) upon yourself, do not seek the peacefulness of existence, do not cross over the river [of existence]. This kind of instructions one should teach and give to the bodhisattva in the beginning of his development. Why? Because this state of the moments of existence (dharma) and nothing else is their [true] state. Foolish people explain things in accordance with moments of existence of arising (utpādadharma) and moments of existence of disappearance (nirodhadharma). But this sphere of all moments of existence (dharmadhātu) distinguishes itself by being beyond thought-constructions, and understanding the essential character of all these moments of existence in this way is awakening. If he is taught in this way and does not become afraid, scared or terrified, then he is a bodhisattva not turning back in his development, one who has a part in the stage of never turning back. By means of this instruction one should carry on a pleasant conversation at length."Bodhisatvacaryānirdeśa, §16
The statement "If he is taught in this way and does not become afraid, scared or terrified, then he is a bodhisattva not turning back in his development, one who has a part in the stage of never turning back.
" gives a strong impression that this teaching is perhaps only going to be fully appreciated and accepted by a non-regressing bodhisattva. An avinivartiya bodhisattva is a long, long way from being a "beginner".
In the Prajnaparamita, it is stated that teachings such as this should only be given to avinivartiya bodhisattvas, or those under the instruction of a kalyana-mitra.