Does this also mean that all action is to be done without any motive behind it?
Not necessarily. All actions is to be done as a duty without expectations and attachment to results. There should not be motive for personal gains or pleasures.
niyataṃ kuru karma tvaṃ karma jyāyayo hy-akarmaṇaḥ | śarīra-yātrā’pi
ca te na prasiddhayed akarmaṇaḥ || 8 ||
8. You must perform your obligatory duties; for action is superior to non-action (meditation). For not even the maintenance of the body is
possible by inaction.
From Ramanuja’s commentary:
If it is argued that any action such as earning money implies 'I-ness, 'My-ness' etc. and will therefore distract the senses, and the Karma Yogi will again be bound through the subtle impressions [samskāras] of his acts then;
Krishan says
yajñārthāt karmaṇo’nyatra loko’yaṃ karma bandhanaḥ | tad-arthaṃ karma
kaunteya mukta saṅgas-samācara || 9 ||
9. This world is bound by actions other than those performed as sacrifice. O Arjuna, you must perform work to this end [for sacrifice
alone], free from attachment.
People become subject to the bondage of Karma only when work is done for personal gain, but not when work is performed, or money acquired for the purpose of sacrifice and other acts of charity which are prescribed in the Scriptures.
So that’s should be the motive or thought process behind doing any actions. Don’t get attached to it but have feeling of let go. As Maharaja Janaka said
"Unlimited is my wealth. At the same time I have nothing. If the whole
of (my kingdom) Mithila be consumed in a conflagration, I shall incur
no loss.