I'm a CS major but by the time I'll graduate I'll have taken more math than CS courses (degree requirements are funny that way). I would tend to agree with you about the relative difficulty if CS and math but this could be partially a consequence of how it is taught. If some school was crazy enough to offer a "real" (see Dijkstra[1]) program that would compare more favorably.

But this sort of proves the original point. Since cs/programming has lower barriers to entry (cool new stuff is still "easy") there are many more opportunities for young people.

[1] http://www.cs.utexas.edu/users/EWD/transcriptions/EWD10xx/EWD1036.html