That was probably their thinking. Time was right. In the past there would
be more CD users. They have wanted to do this for some time, but were
reluctant to cut off new users from trying Ubuntu.

What bugs me more is the loss of the Alternative disk. They are removing it
without being able to implement all of the parts into the regular disk. If
you want RAID you are out of luck till the spring. Bad decision. Do not get
rid of something till you have the replacement ready.
....softpedia.com/.../Canonical-Drops-Alternate-CDs-from-Ubuntu-12-10-2\
89338.shtml

I don't have a problem in principle with going with one ISO, especially now
they are increasing the size. I have a problem with the decision making
itself and what it says about Canonical and how it treats its users. What
is the sense of having RAID with 12.04 and 13.04 but skipping it in 12.10?
There is no consistency nor, it seems, does there need to be. We will do
what we want and you can like it or leave attitude. What would it have
taken to wait on this till everything was ready? They are jumping the gun
for no apparent gain and potentially ticking off users and giving bad PR.
Again. Why are they repeatedly poking a stick in their own eye and then
wonder why people jump all over them? Things were just going well after the
last fiasco.