There is a very compelling reason why we need to undo the damage to the quality of spoken English around here. I mean, Singlish is fine for friendly, personal, letting-yourself-go social conversation. This localized lingo is one form of culture we can truly say developed naturally from our little island, and is a touchstone of our identity at home and abroad, but it simply won't do as a medium of academic discourse. Especially if the local version of the language is the only one we use, but our written secondary and post-secondary language exams are set and graded by language academics in Cambridge, England.
But exam grades are just one little thing. Rubrics and tolerances balance each other out and collectively, grades simply point which direction the wind is generally blowing. What matters more is the level of engagement our kids have with texts that are not primarily written in the local vernacular and responding to them at the same level.
It's not a matter of which version is 'superior' or 'inferior' but rather whether one's command of language either facilitates or impedes understanding between people trying to communicate with one another. If there is no or little understanding, then there is a failure to communicate. In school terms, either the text is not getting through to the candidate, or the candidate isn't getting through to the marker, or both. Whichever, that is what the 'FAIL' grade pragmatically represents.
But that's just the grade. On the grander scale, too many people stuck in Singlish mode, unable to code-switch to the standard English of academic and intellectual discourse means too many Singaporeans being unable to participate in and contribute to complex and abstract thought.
If this is true, then our Colonial Masters haven't really left. We've just made it easier for them to give us our orders because we're proud to have 'upgraded' ourselves to speak a little more like them. But with this level of language ability, we are still unable to view them on equal terms.