He's 4 yrs old; that's hardly a baby.
As far as I'm concerned, four years old is a baby.
Besides the fact that males are not a seperate species,
The conduct of more than a few could easily lead one to think otherwise.
Stop the pussyfication and let males be males again. Otherwise you get 'men' like our neighbours where the dad doesn't dare to say 'no' to his 16 year old son, because the kid will throw a crying tantrum...
I would think letting the little guy cry IS infact letting that particular male be himself.
Not letting him experience his own natural expression of feelings, insisting he "man up" is what leads to parents fearful of their little boys crying.