First, let's point out that it's right to warn people against the sin of idolatry. Note that all this was directed according to divinely inspired writing. The fact that one had to look at the bronze statue of the serpent in order to be healed shows that statues could be used ritually, not merely as religious decorations. Catholics use statues, paintings, and other artistic devices to recall the person or thing depicted. Just as it is helps to remember one's mother by looking at her photograph, so it helps to recall the example of the saints by looking at pictures of them.
Catholics also use statues as teaching tools.
In the early Church they were especially useful for the instruction of the illiterate. Many Protestants themselves have pictures of Jesus and other Bible pictures in Sunday school for purposes of teaching children, especially those who haven't learned to read. Catholics also use statues to commemorate certain people and events, much like Protestant churches that have three-dimensional nativity scenes at Christmas. But the fact is, there's no idolatry going on in these situations. God forbids the worship of images, but he doesn't ban the making of images in general.