It seems completely morally bankrupt... If instead of Russia it was ISIS, would they still send money just so they have cheap gas? Like at what point would they stop? Do the Russians need to be impaling babies and goosestepping through Red Square?
I also don't understand why Ukrainians don't feel a deep sense of betrayal about this
They are (arguably) playing for themselves first.
Actual EU action in this conflict has been pretty well aligned with citizen/voter interests in my opinion; this is not strictly a good thing, you could uncharitably call it "emergent unprincipled EU hypocrisy".
Many voters want energy safety, inflation to be kept in check and to minimize spending on foreign conflicts and national defense. Lots of Europeans agree with keeping Russian expansionism in check, but they don't really want to pay for it nor risk escalation.
Generally, sacrificing trade for ethical/moral reasons sounds like an easy sacrifice to make, but this comes at a real price (getting overtaken by "immoral" nations that don't, possibly ending with ethically worse global situations in the long term), and things like this get fierce opposition in a democracy where you have to balance ideology with the economical well-being of your voters (ideological voting is much more achievable if you can at least pretend that it aligns with economical self-interest somewhat).
To me, EU feet dragging in the Ukraine war is a bit sad but unsurprising.
Morality wise, I'd say several middle-eastern petro-states are significantly worse than Russia (non-democratic government, human rights violations at large scale epsecially against foreign workers), and trade with those has been going on for decades...
But yeah, it is not great look for democracies when they can't support good causes because it will cause harm domestically which leads to less votes.