CAS question

As I have made no secret of the fact that I think symbolic manipulation software should have a major role in mathematics education starting no later than Algebra 1, I tend to get into a lot of discussions with folks who do not quite agree with me.

Not too many years ago graphing calculators made their appearance in high school math classes. They were pushed down from the top, so to speak. By requiring students to have them for the 1995 AB and BC calculus Advance Placement exams, teachers were forced into using them. What happened? Almost overnight those teachers and their colleagues saw how much more students could learn and understand using graphing calculators. I doubt very many would give them back today.

The very first models graphed and did numerical computations. Very quickly the ability to make tables of values of functions and software to do sophisticated statistical calculations were added.

(Side track: That first year, 1995, I used the TI-85 which did not have a table feature and half my class showed up with HP-48s (don't ask) which did not have a table feature either. What to do? I wrote a program for the TI-85 to make tables and one of  my students wrote a table program for the HP-48 (in assembly language no less). We shared them and then everyone had a table program)

Today, computer algebra systems, CAS, include those features and also include the ability to do symbolic manipulations. (And more actually: dynamic geometry software and computer like document handling are features of the newest models.) While CAS do all the graphing and numerical work that graphing calculators do, the acronym CAS has come to refer to the symbolic manipulation features alone.

So here is my question: Since the graphing, table, statistical, and geometry features of the CAS have been embraced, why not also symbolic manipulation features?

Any ideas?