How would it change the meaning in any way? let me give some examples:
"If I may ask why will you not delete a users account if they want it deleted?"
"If I may ask why wont you delete a users account if they want it deleted?"
"If I may ask why dont you delete a users account if they want it deleted?"
We could even try a fill in the blank! Given the context of the OP you should be able to deduce the missing word.
"If I may ask why will you _____ delete a users account if they want it deleted?"
"If I may ask why _____ you delete a users account if they want it deleted?"
Lets be real here, the only realistic, reasonable and logical options you had at interpretation are those listed above. Did you really think I meant something like this:
"If I may ask why will you esophagus delete a users account if they want it deleted?"
Obviously those are the most probable, but I'd like to make sure I'm actually understanding what the other person is saying. For example, how do I know you didn't wildly misunderstand the OP, put in another word accidentally and actually meant:
If I may ask why will you delete a users account if they want it deleted?
Either way, I'm really losing my ability to give two craps about this sort of thing, so let's get back on topic, shall we?
Why won't I delete an account? Because as I said, posts are here to stay, and since they are, there's most of the time no good reason at all to delete an account if you're not going to delete the posts associated with it. Put something bad in your username? I can change it. And everything else can be edited by the user. As such, I don't want to get a bunch of dumb requests from people to do something that's, in the end, very pointless and just creates unnecessary work for me.
However, if someone can think of a good reason to delete an account but not the posts, I'll reconsider the policy.