When comparing QWERTY vs AZERTY, the Slant community recommends QWERTY for most people. In the question“What are the best keyboard layouts for programming?” QWERTY is ranked 5th while AZERTY is ranked 18th. The most important reason people chose QWERTY is:
You don't have to carry your own keyboard everywhere, QWERTY is pretty popular.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Popular
You don't have to carry your own keyboard everywhere, QWERTY is pretty popular.
Pro Default keyboard shortcuts
The keyboard shortcuts for most applications were designed with QWERTY in mind.
Pro Good for Vim users
Vim is most natural in QWERTY, since this is the layout it was designed on. Learning a good editor will help with your programming a lot more than learning a new layout.
Pro Easy access to important keys
Some of the most used keys in programming such as ; . / " | ' < > * are very easily accessible because they either have their own keys or are "shift options". People who grew up using alternative layouts, such as Belgian AZERTY, know from experience this shouldn't be taken for granted.
Pro Nearly unavoidable for French people
Most of us learned to type with this kind of keyboard, switching can be hard, and impractical to type French.

Pro HJKL intact for vim
Vim programmers are going to want their navigation keys to relate to each other in a sensible fashion. QWERTY and azerty seem to be the only games in town for this
Cons
Con Not an easy to gain speed on QWERTY
Learning to touch type using traditional touch typing methods, you would not be as fast as others on Dvorak and you would be making quite a few mistakes.
The reasons that most of record holders have placing in typing speeds is because they do not use traditional typing methods.
Con Made for typewriters, not computers
It was created before computers got popular. This layout was created for typing machines, so as to prevent collision between character hammers from slowing down the typist.
Con Very unintuitive
Why QWERTY?
Con Correct typographic letters and symbols not easily reachable
Con Bad for programming
But you get used to it... :-)
Characters very common in programming languages, like [] {} ~#|`@ are reachable only via the infamous AltGr key on Windows computers (and perhaps Linux ones; not sure for Macs).
With practice, you type them without thinking, but it is still a rather impractical gymnastics.
Con CTRL + / is only accessible by numpad
