Depends on how you look at it.
It must be remembered that sickness and death are great, great evils; they were not "supposed" to be a part of this world, and came about as a consequence of the sin of Adam. Christ, of course, conquered the tomb and gives us the hope of eternal life. Catholics, then, look at death for what it is -- an evil -- but cling to the hope He offers, trusting in His Divine Mercy while also realizing that He is Just. Christ Himself wept before the dead Lazarus.
In that context, prayer for a dying Pope makes sense.
Cheers,
Scott.