Yes. The reason Britain and France declared war on Germany was that Germany invaded Poland and Britain and France had treaty commitments to defend Poland. (They also had treaty commitments to defend other Eastern European countries, which they decided not to honor when Germany invaded those countries before it invaded Poland, but that was because their governments erroneously believed that Hitler would stop invading countries if they appeased him.)

> I thought the primary goal (of the Allies) was to defeat the Axis powers because they were directly attacking the UK and USA.

Germany never directly attacked the US. (Japan did later on, but that was on their own initiative; they never discussed any overall war plans with Germany.) And when Britain and France declared war on Germany, Germany had not attacked Britain or France either. As I said above, they declared war when Germany invaded Poland.

I think though, that the average Brit did not care so much about Poland. It was clear by that point that Hitler intended to take all of Europe and the exact event that triggered it was maybe not so important. After all it's not like France was wrong to declare war - it was obvious that they were going to be next.

After the Nazis invaded France, I expect that's true, yes. But before that the only reason for Britain to be fighting was over Poland.

> it's not like France was wrong to declare war - it was obvious that they were going to be next

No, it wasn't at all obvious. Hitler's stated purpose, going as far back as Mein Kampf, was that Germany should expand to the east. His decision to move west instead was rather sudden and surprised a lot of his own advisors. And didn't happen until eight months after Britain and France declared war (the intervening period was called the "Phoney War" even at the time).