Company running buses is at the losing end? Well, depends how do
you look at it.
Why would it lose money? Because commuters dont prefer taking
buses.
Why would commuters not prefer taking buses? Because many of the
bus routes takes much more time compared to trains going to the
same place. (Could also be because its not as reliable)
Why does it take much more time? Because some of the routes are
so long and winding!
If the routes stays the same as they are now, people will just
continue taking trains. In this case u can effectively say that the
bus company is giving up competing with trains. It's not
competition at all. This is actually what is happening. Look at
some services like 502, it takes just as much time to get to a
place as the trains, but costs more. If its not charging express
fares, i would gladly take it everyday instead of the trains.
That's competition.
Futhermore, do you really think the services will not decrease
with competion of the new rail lines if the system is being kept as
what it is now? Many of sbst's own bus services will compete with
its own downtown line when its completed (less bukit panjang).
Would they maintain their bus routes and frequency after the
downtown line is built? The pool passengers are the same (with some
increase of course), but the cost will go up if they operate 2
modes of transport out of the same area.
Just my 2cents, cheers 
Well, you do have a point here. I guess the entire system is
pretty much in a messy state with central planning (when was the
last time a new trunk svc was introduced excluding Sv84),
non-duplication of routes..
Apart from the long-winding routes that may deter commuters as
you mentioned, most of the time it is road congestion that
affects the commuters' decision (even when the bus route in
question is not long winded). Road congestion is certainly
beyond the capability of bus companies to resolve and this
situation certainly would not disappear in the near future even
when car growth rate was announced to be capped at 0.5%.
These hiccups in travel times paint an impression of buses being
inefficient and unreliable (though we have seen how trains can
be equally unreliable after this week's drama
:D) and I believe many would find rail travel more
attractive..
With regards to your last part about DTL and competition with
SBST's own routes, I feel that that was perhaps why DTL was handed
to SBST. I just find the whole multi-modal PTO concept a false
front to ensure that both PTOs (mainly SBST) can survive in
the rail-dominated land transport of the future (as intended by the
govt).