Sure, it may be the only way to "get the shot" but from a photography perspective it's kind of like cheating because there's no skill required on the photographer's part in knowing when to snap or compose.
That is so unbelievably naive I don't even know where to start!!! Go read Art Moriss' blog, or any one of the worlds most renown bird photographers. MOST will tell you they are not good at BIF (Birds in Flight), because it takes a tremendous amount of detail-oriented SKILL. Good BIF photography requires dedicated practice to get right, as there are so many factors to consider, all of which must be continually addressed in real time!
It is not simply a matter of point, frame, and shoot. Achieving and maintaining correct exposure, particularly of birds, while they are in flight against a constantly changing background, is one of the most challenging things in photography. You've just shown your excessive naivete with the claim you've made above. Snap and compose my ***. You just insulted the entire community of bird photographers, particularly the experts at Bird in Flight photography.
I have been trying (and failing) to get some decent pictures of chikadee's in flight. Do you have any idea how freaking fast those tiny wings flap..... and they don't fly level..... it's flap like crazy and climb, then tuck the wings in and go ballistic.... then flap.. then ballistic. It has to be the hardest thing I have ever tried photographicly.... taking pictures of the ISS was childs play in comparison.
Hah! Indeed! Getting a good shot if a perching chickadee is a chore...those little twits never stop moving, even for an instant. Even my best shots of chickadees have some blur somewhere on the bird (even in long sequences if 16 or more with my 7D). You need very high shutter speeds to capture them in flight, and a proper flight setup is pretty much essential.