Harmony with TypeScript

Not so long ago Microsoft announced a new language, targeting on front-end developers. Everybodys first reaction was like Why on Earth?! Is it just Microsoft darting back to Google? Is that a trick to promote their Visual Studio?

But anyway, whats wrong with JavaScript? Why everybody is so keen to replace it? JavaScript for a language designed in only 2 weeks is freakishly powerful and flexible. But JavaScript still has its bad parts.