I think that nicknames come naturally, and that they should be considered when using certain names, because the probability is high that the nickname will be used, even if not by the parents. I also think that some names almost demand a nickname, because most people are not going to want to pronounce the full name every time they speak to or refer to the person in question.
So,for example, my sisters are named
Patricia and
Pamela, and are always called
Patty and
Pam. I think that
Patricia and
Pamela are two of those names that almost demand a nickname, and that it would have been foolish of my parents to use those names if they disliked the nicknames. Apparently my parents planned from the beginning to use those nicknames, because they are what my sisters have always been called, and I do not think there is anything wrong with that.
Then, some names are on the fence. There are possible nicknames for them, but they are not inevitable.
My name is
Janice, and it is possible to get the nickname
Jan from it, and I have no doubt that some Janices do go by
Jan. I never have. No one has ever called me
Jan, and I am glad because I do not like it. But I think
Janice is one of those names for which a nickname is possible, but not inevitable.
And then (I just posted about this, actually) I named my daughter
Victoria, another name for which a nickname is almost inevitable. I decided from the beginning that we would call her Torrie, for I knew that if we just called her
Victoria, people would start calling her
Vicky, and I preferred Torrie. But, I did not hate
Vicky, I just preferred Torrie. I do not think that you should use a name if you hate a popular nickname for it, because the child may end up being called by the nickname anyway.
I am sure that there are some people out there who have what I call a name that almost demands a nickname, and do not go by a nickname, but I bet it is a constant effort on their part to get people to use their full name all the time.
So, obviously I do not think there is anything wrong with saying, "I will name my child x, but call her y" because I did that myself. I also do not think that a nickname has to develop, though sometimes they do. I think it is fine for the parents to decide upon a nickname at birth.
For those who strongly dislike nicknames, I think that they should try to pick a name that is nickname free.