ACCA's a qualification, not really equivalent to a degree. Beyond level 2, it's supposedly harder than a normal degree. And it's passing rates are dismal, so technically, the standards are higher. But ACCA is pure accounting, and not as well rounded as the curriculum in NTU/SMU, where general electives and core electives such as calculus, art, history etc are offered alongside the usual rigor. Besides, accounting degrees are usually easier to complete since there is a lot of moderation going on. SIM-UOL in Accountancy is a good degree, and the merit of its curriculum undisputed, but it's still a private degree after all, there's a stigma associated with private degrees that the students who enrol are of a lower quality, since the entry requirements are much lower than the local grads. Whether it's true or not is controversial, and i'm want to emphasize that is not my view and i believe the quality of a person is not determined by his or her grades.
Hence, People would take the ACCA to strengthen their resume. For example, there was talk in the forums that big 4 don't give a lot of recognition to UOL acctg degrees, and would actually give priority to ACCA holders. But then again, ACCA without a proper degree is detrimental to career progression. Yet, a private degree without ACCA makes it hard to get into Big 4.