John Anthony West has a different view on the pharaoh mummies.
If you watch this amazing series about Eygpt
http://topdocumentaryfilms.com/magical-egypt/
In episode 5 he mentions how they mummyfied the bodies to make sure that the souls would NOT come back on earth. As if having ascended was the ultimate gift and previledge. By mummyfying the bodies, they made sure that it would be preserved in its final state, which was without a brain and organs, therefore redering the body unusable forever. This granted the pharaoh's a guarantee to never have to come back onto this lower plain.....
I highly recommend this series as it is most amazing.