Limited Intelligence; Limited Results.

In the next four verses 7-20, 21, 22 and 23 Lord deals with the "Common Man" who is neither EVIL DOER nor a NOBLE SOUL.

EVIL DOER is the one whose knowledge is completely stolen by Ignorance.
NOBLE SOUL is the one whose knowledge is fully restored by surrender to Supreme Lord.

कामैस्तैस्तैर्हृतज्ञानाः प्रपद्यन्तेऽन्यदेवताः।
तं तं नियममास्थाय प्रकृत्या नियताः स्वया।।7.20।।

kamai, te, te, hruta-jnanah, prapadyante, anya-devataah
tam, tam, niyamam, asthyaaya, prakrutyam, niyataam, svayaa.

Those whose knowledge is stolen by desires, they take refuge in other devatas led by their own natures.

यो यो यां यां तनुं भक्तः श्रद्धयार्चितुमिच्छति।
तस्य तस्याचलां श्रद्धां तामेव विदधाम्यहम्।।7.21।।

yah, yah, yaam, yaam, tanum, bhaktah, sraddhyaa, architum, ichhati
tasya, tasya, achalaam, sraddham taameva, vidhadhaami, aham.

whatsoever form any devotee want to be devoted with faith, I give them that unfailing faith in that form.

स तया श्रद्धया युक्तस्तस्याराधनमीहते।
लभते च ततः कामान्मयैव विहितान् हि तान्।।7.22।।

sa, tayaa, sraddhayaa, yuktah, tasya, aradhanam, ihate
labhate, ca, tatah, kaamaan, maya, eva, vihitaan, hi taan.

With that sraddha (which is given by supreme lord) one engages in "aradhanam" worshiping of that form; he will get the desire fulfilled as ordained by me alone (the supreme lord).

अन्तवत्तु फलं तेषां तद्भवत्यल्पमेधसाम्।
देवान्देवयजो यान्ति मद्भक्ता यान्ति मामपि।।7.23।।

antavattu, phalam, teshaam, tad, bhavati, alpa-medhasaam
devan, deva-yajo, yaanti, madbhaktaa, yaani, maam, api.

Limited are those fulfillments; That for the men of small-intelligence
The worshipers of gods go to them. But, my worshipers reach me alone.

Key points:
1. As desires start stealing the original jnana (and viveka) one starts approaching the limited controllers of material powers. The controller of each energy is a GOD.

2. As long as such devotion to a limited energy source is based on FAITH such faith is strengthened by the LORD; For each individual goes as per his own rules based on his own nature.

3. With that strengthened FAITH, one devotedly puts in effort for achievement of his desire, the fulfillment if ordained by the supreme lord alone according to the sraddha and aradhana (work/effort).

4. MOST IMPORTANTLY, all such fulfillments are "temporary" (antavat - having an end). So, an ordinary BHOGI will continue to WORK, and GET the RESULT. The WORK is FINITE and the RESULT is FINITE. Those who are of little intellegence they keep going to the FINITE manifested "GODS" and keep getting the FINITE manifested RESULTS.