It would have been disrespectful to the sanctity of the objects of the Tabernacle for them to remain lying out and uncovered for all to see. Alternatively, one might note the Torah's usage of the plural in describing the making of these tapestries. When describing the other componants, the Torah uses the singular. It was only through weaving the tapestries that all the craftsmen contributed their talents. Betzalel, therefore, instructed the craftsmen to first construct those objects to which everybody would be able to contribute their talents.
Most societies tend to stress one way over the other.
Judaism, however, teaches that both are correct. Please pass it on to a friend. SUB bytetorah .