I agree that the Macro events were a factor for WP in 2011 and PAP in 2015. But it also shows that WP had nothing else in the tank if they relied solely on Macro factors. The article drives home the point that both WP and PAP are now more or less feeding in the same pond - centre left. PAP swung back to feed in the same pond. WP has to re-strategise if not people will have choose between one party with resources and ability to deliver and one without and both with the same ideology. (Note I am simplifying this for argument sake).
There are many ways to differentiate even with similar ideology that citizens want. Take on more prominently ( prominently is the operative word here which means in local context to some extent confrontational) the lapses, the abuses, the double standards and be bolder with policy differentiation.
Gone are the days of press statements and listing of questions raised.
We can disagree on the details but where should WP stands in the political spectrum to put them in better position to appeal to the masses. This will ultimately determine the general direction the party is heading. Going too far left will lose appeal to the middleground, leaning to the centre will offend the opposition hardcore. So this is a delicate balancing act.
As for those issues you raised, it the small details on how a party should attack the issues. The style, presentation and even tone of voice all affect public perceptions. You attack pap policies hard but at the end of the day come out with an alternative proposal that is nothing more than a scale down version of the original one. Nothing wrong with it as I often see this playing out in other parts of the world. The yardstick I measure politicians are whether they give themselves sufficient space to manevour when they propose something or say something. This is something I find lacking in sdp and I am sure many swing voters also notice it.
As far as WP is concern, I don't see why should they get too confrontational just to satisfy the desire of a certain segment of the opposition base. Most opposition voters will still vote WP simply because they are the only party with a realistic chance of beating pap. WP will only get confrontational when they sense their opposition supporters are fast losing patience and abandoning them.