What language failure? Where got fail? How affect business or economy? Singapore is among Top 20 (if not Top 10) GDP-per-capita rankings in the world. Now don't tell me that money and income not important compared to so-called heritage, look at the foreign laborers and maids and even prostititutes who came here to serve Singaporeans. They kept their native first languages, don't they?
Language is just a medium for communication. Excessive emphasis among any linguistic group or race is just political fascism or fanatical idealism. If the majority of Singaporeans choose to abandon English, I don't mind too, in the principle of proportionality as well as the spirit of democracy. But if a minority few start trying to mount on moral high horse for certain agenda, that's different.