I refer you to post 42 lord spandex smasher. Or indeed the following:
http://www.skybrary.aero/bookshelf/books/2263.pdf
1.3.2. Minimum Control Speed in the Air: VMCA
JAR 25.149 Subpart B FAR 25.149 Subpart B
“JAR/FAR 25.149 Minimum control speed
(b) VMC[A] is the calibrated airspeed, at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the aeroplane with that engine still inoperative, and maintain straight flight with an angle of bank of not more than 5 degrees.
(c)VMC[A] may not exceed 1.2 VS with
• Maximum available take-off power or thrust on the engines;
• The most unfavourable centre of gravity;
• The aeroplane trimmed for take-off;
• The maximum sea-level take-off weight
The aeroplane in the most critical take-off configuration existing along the flight path after the aeroplane becomes airborne, except with the landing gear retracted; and
• The aeroplane airborne and the ground effect negligible
(d) During recovery, the aeroplane may not assume any dangerous attitude or require exceptional piloting skill, alertness, or strength to prevent a heading change of more than 20 degrees.”
If you call stalling flying then I think we have to agree to disagree, certainly in the context of transport category aircraft taking off. I also doubt you would be trimmed for take-off at that speed.
I guess that if the tail is infinitely long or the rudder is infinitely big theoretically vmca is zero. Doesn't get us a lot further though if you can't get off the ground at that speed.
Since the rudder and vertical fin cause drag, I reckon that manufacturers like to keep it as small as possible.