Let's compare:
A) Tell children there is a Santa, and later they find out the presents came from Mom and Dad instead.
B) Tell the children that Armageddon is so close that they'll never graduate from school, get a job, get married, raise a family. Then when the kid is about 40 he finally realizes the WT was completely full of lies and he decides to leave it all behind and finally get a degree and career, then decide at this late date if he still wants to get married and have a family.
I'm living option B. In retrospect, I would have chosen option A. If I decide to have my own kids, I'm going to take my chances on option A with them.