Claims about the relative simplicity or complexity of different languages are rarely grounded in actual linguistic evidence. Languages comprise so many parts that it's not even clear what the basis of comparison could be: is English, a language with highly restricted word order but without grammatical case marked on most nouns, more complex than Russian, a language with comparatively free word order but a highly articulated case system? Who can say?
With that in mind, the statements about Bahasa Indonesian being simpler or more rigid than other languages are more like social or cultural judgments than bonafide linguistic facts.
With that in mind, the statements about Bahasa Indonesian being simpler or more rigid than other languages are more like social or cultural judgments than bonafide linguistic facts.