What this PE clearly shows is that if the choice is hardcore PAP, hardcore opposition, or a moderate compromise, the moderates will have the lion's share of the votes. The spoiler in this instance was TKL, wholly unpopular with all three, but who plainly drew more votes from the latter two than the first.
When the choice is between just the PAP and an opposing faction though, the tendency is for more moderates to swing to the "safe" side of the PAP, rather than risk it with the opposition. Clearly then, the ONLY way to win an election in this country is for the opposition to head towards an extremely centrist, non-confrontational sort of platform ala LTK/WP. As galling or untasteful as that may be to the likes of TRE and its readership...