I am an 1980s kid... so my point of reference may be biased.
Singapore was still okay up until the turn of the millennium. It's only from the mid-2000s onwards, and after Pinky had ascended the throne, did things go south.
Before that, there were quite a few assorted, perhaps seemingly unrelated happenings which seem to suggest that we're ruled by a bunch of idiots. For example, Haw Par Villa's 'revamp', the Tang Dynasty 'project', the increasing commercialization of Sentosa, the closure of Satay Club, renaming Marina Bay as Marina Bay, the Budget Terminal etc. Individually, these events were mere annoyances, but when combined together, they seem to suggest there's a very real, underlying systemic flaw in Singapore.
Of course, the numerous scandals in recent years further highlighted this flaw.