Why are video tape recorders built with rotating video heads instead of static ones?

The video data is striped diagonally across the tape so more data can be saved on the tape. The rotating head is angled and writes the data in stripes, this essentailly stacks the data using most of the width of the tape. The rotation allows the head to move faster than the tape speed to accomodate the increased data storage. The remaining width of the tape is used for audio which is recorded in two continuous stripes.