Another MRT mystery?

I was catching up online on the current hot issues about the impending Comfort Taxi fare hikes when I came across an article I had missed a few days ago.
This article left me a bit confused and bewildered and I actually had to read it a couple of times to make sure I understood it correctly.
To tell you the truth, I still don't quite get it.

Here it  is, I ask you to read it and then explain to me, if anyone can.
It's from the Channelnewsasia.com online site published on 2 Dec 2011.

(Please click on article to enlarge)

The good news is that MRT will be adding more trips to alleviate the expected Christmas shopping crowds and New Year's day revelers.
My head is spinning with this good news because I can't rationalize how are they able to do this?

I distinctly remember all the hoopla over the over-crowding issues and the letters from frustrated commuters over the issue. The replies from the operators ranged from "the train ware at full capacity, the signaling equipment is unable to cope, new trains have been ordered but will progressively be installed, to expect delays for 3 to 5 years, etc etc..." 


Now I am confused as to how they can increase the trips and cut train arrival interval only for Christmas and the New Year periods.
WHY CAN'T THEY DO THIS ON A DAILY BASIS?
Commuters don't need to be packed like sardines going home from work each day.