I looked it up on OED - you’re right (sorry for any doubts) it is a back-formation. However, I might object to “just looking around” and “coming [as opposed to ‘come’] to” since it shows it having been around for nigh on a hundred years 
I agree that using more complex grammar in order to sound clever is annoying. Like the people who correct you when you say ‘he gave it to John and me.’ (‘Me’ is correct; it is the object, not the subject).
However, I do use whilst (I’m British), because ‘whilst’ to me does not have exactly the same meaning as ‘while’. ‘While’ is more general, ‘at around the same time,’ or comparing two different things, whilst (;)) ‘whilst’ is ‘at exactly the same time’ or comparing two objects of exactly the same class. I use it for precision, not pretentiousness. I do remember reading a better definition of the difference between the words years ago, but sadly haven’t been able to find any cites for it today.
Of course I’m the kind of person who occasionally has to hold back from using words like ‘heretofore,’ because although it’s a concise way of conveying the meaning I intended (‘before this moment, this state existed’), it also conveys the unintended meaning of being a pretentious git.