Can you imagine/or try squashing a King or Queen quilt into the throat area of a domestic machine to quilt it? It is rather difficult, and considering an embroidery hoop needs this whole area to move around makes it more difficult.
One of the best ways to do this is to quilt a block as a 'sandwich' [background, batting and backing] You can then use sashing or other methods to join these blocks. Or you could make the quilt in sandwich strips of, say, 12" wide, and quilt, then join another sandwich strip and repeat. Another way is to make the centre block first and quilt, then add blocks around the four sides, quilting as you go, a bit like the log cabin block. Some good sites to check these methods out are Jenny Haskins and Kenny Kreations. Hope this helps