hmmm
my take is that-
in the real world, your deposit is still your investment, your rent minus tax,costs,mortgage, etc is your yield on that deposit. the value of the house can go up or down and until you own it outright or sell it , its perceived value does not actually put more money in your pocket unless you use its equity which is another,seperate, investment ,
if house prices fell and you were forced to sell,the real money you would lose is your deposit,and the diffrence between the mortgage and sale price which hopefully you would be keeping an eye on and not let get too lopsided.
i suppose thats why they call it investing.
sudden.
and it is because house prices can fall that i think this is a more practical way of looking at it,