My experience with a baby was quite the opposite.  In fact, having a
never-still baby was a very large factor in my purchasing of a DSLR in
the first place.  A year later, I have 1,000 more reasons to prefer it.

Point and shoots take forever to focus on anything.  Since focus logic
is contrast based, a moving object poses an even more difficult time for
their focusing because motion means no more static contrast.  (I was so
sick of that yellow square which is the camera's way of saying, uh, I
don't know, maybe this?)  Sometimes you can pan with the object and the
camera will cope, but a moving animal sometimes leaves you no options.
When you are trying to nail an expression or event, a point and shoot
can frequently present quite a challenge.

A DSLR camera focuses very quickly in comparison, *especially* when
using the in-the-lens motors.  When you can concentrate your focus point
on a small dot, or small square, this helps immensly too.

Is the light level getting dimmer?  If the answer is yes, then that
point and shoot is going to lose 80% of it's ability to focus unless you
shine a flashlight on the subject (a number I just made up with a
guess).  Yes, they have built in illumination for autofocus assist, but
they often miss the mark.  In any event they burn more battery.   Manual
focus is possible but takes a very very long time to set and you have a
measley little LCD screen to go by.  Manual focus with a DSLR is
do-able, but for me is irrelevant due to AF being faster than I am and
more accurate than I am.

I can focus with my DSLR in comparatively very dark circumstances
without any kind of auto focus illumination, which I have disabled
anyway.

Depth of field was another big motivation for me.  I think I'm nearly
alone on this, but I don't want the childs face in focus right along
with the wall 9 feet behind.  I want sharp facial features and blurry
background objects.   Point and shoots, with their small sensors force a
very large depth of field no matter what f-stop you choose.

Battery life; I think I got about 180 or so exposures, typically fewer
shots than would fill a 256 card at 1.5MB each.  In comparison, I charge
my DSLR battery about once a month, or every 1000 shots or so.  The
onboard speedlight is never used, only an external flash if needed, and
that uses rechargeables which were $1.00 each, and with my usage rates,
last about a month as well.    

I prefer my glass viewfinder to those LCD screens.  After about 1 day, I
never wanted to go back to an LCD for preview.

When your baby is asleep and you want to take a long 20 second exposure
in that darkened room, the SLR photo yields a lot less digital noise, so
that when you review that picture of your sleeping baby 8 months later,
the absence of the digital noise changes your life.  :-)

For exactly that reason I found the dSLR to be so much better
(it's usually quicker to switch on, focus and shoot without
the lag of p&s cameras).  Having good capability in natural
light is also a bonus.