"We love beautiful traditions of our country."
Translation:Chúng tôi yêu những truyền thống tốt đẹp của đất nước chúng tôi.
Because it adds more oomph and is more poetic. Tốt (good) + đẹp (beautiful) combine to mean beautiful but to a higher degree than just đẹp. On the other hand đất nước is where the native Vietnamese word for country came from. Literally the earth and water combines to mean country although the more formal term is borrowed from Chinese quốc gia (國家).
Vietnamese (the language) is full of pairings often done through alliteration. One such example involving the word beautiful is đẹp đẻ (beautifully born) which is a very big complement for a person (mostly females). On the other hand xấu xa (in this case the word xa is just used for alliteration) is a very big insult meaning ugly/bad (attitude).