They are absolutely correct to believe that, and of course the best challenge to Putin's regime is to fairly engage with Russia as a whole. The very last thing we should be doing is refusing to have anything to do with the country.
On at least one level the Russian invasion is entirely understandable (which is obviously not to say excuseable) - a Ukraine that becomes less corrupt and less unequal, and sees its population gradually improve its quality of life, is a serious threat to the stability of the Russian regime.
But that's not the point. The issue
@Drico isn't 'Kraut bashing', but rather highlighting the somewhat unpleasant reliance on Russia that emerged.
Russia will always have to be reckoned with, however I am less confident in the belief that Germany has moved on from this convenient economic relationship.
Right now, it's a different kettle of fish, whereas looking for the future an olive branch (not sending offensive tanks) is something that may reap financial rewards.
Yet, the risk of not supporting Ukraine with armour has to be considered as well, because the fall of Ukraine could easily have its own dire consequences.
Again, not now as Russia will struggle for the next decade at least, but an emboldened Russia and its cronies is a legitimate threat to Eastern Europe.
It's not about destroying Russia nor is it saying there should be no engagement, yet within it is best to secure a position where they'll come to the table.
Without armour, Ukraine's sovereignty is at real risk and an emboldened Russia, with its war justified from their perspective, is not good for Germany.