The primary purpose of Ares 1X was to monitor thrust vibrations near solid rocket booster burnout and their effect on vehicle vibrations and dynamics (If you care about the specifics I can go into them). Computer simulations suggested that these would be a serious problem, enough to kill the whole Ares I concept, but instruments on the shuttle SRB's did not show this to be as serious, but partially because of the shuttle design. NASA needed a better test of the effects of thrust oscillation, and it needed to be as soon as possible. So, the "fake" parts weren't just to make the rocket "look" like an Ares 1, but to make it behave like one in flight, which was the point of the test. These "fakes" weren't just pieces of metal bolted together for aesthetics, but were engineering mock-ups to best simulate the weights and characteristics of the parts they are standing-in for. Since the test should be done as early as possible, it makes sense that a lot of the "real" parts aren't ready, but NASA can still test the closest things they have available. Also, this article implies NASA just used an off-the-shelf guidance system, which is not exactly true: the control laws are the same as the ones which the real Ares I will use if it's built.

In short, although I do not deny that this test was used for political reasons, the test was planned long before the Augustine commission started, and has real engineering value that is critical to the Ares I program, which is definitely not what the above article implies.

To review, Ares 1 will cost about $1 billion per flight because of the low flight rate and the huge shuttle infrastructure costs. Even if NASA gets another $3 billion per year, Ares 1 won't fly until after ISS is scheduled to be destroyed. Meanwhile, the requirement to support the ISS has driven up Ares 1 and Orion costs. It could cost as much as an additional $6 billion per year to afford both ISS and Ares 1 after 2015. So without ISS, Ares 1 has nowhere to go for a decade while Ares 5 is developed. Does anyone really think that five Congresses in a row will pay $ billions per year for a program that goes nowhere and does nothing? This plan has the death of NASA written on it.