But by your own reasoning, you're also saying it's reasonable to learn Russian as a way to better understand Russia because your country happens to be opposed to them.
If you accept that this relatively obscure reason is a valid motivation (which I agree it can be) then you must also accept that there are all sorts of other motivations that are equally valid including "so I can speak to emigrants" or even just "because I find it fun".
It's not an obscure reason, many people engage with the enemy professionally. That's one of the most frequent motives to learn a language probably. Either you want to immigrate to a country or you want to conduct business with it or it's your enemy and you need to undersrand it. First two options are out for the Western world at the moment
If you accept that this relatively obscure reason is a valid motivation (which I agree it can be) then you must also accept that there are all sorts of other motivations that are equally valid including "so I can speak to emigrants" or even just "because I find it fun".