English is not popular because it is "easy to copy" or any nonsense like that. English may not be easy to copy but it's comparatively "bland". "Bland" in this

English is not popular because it is "easy to copy" or any nonsense like that. English may not be easy to copy but it's comparatively "bland". "Bland" in this case means "has a smaller number of marked features". For example, it has no tones. It's always easier for someone speaking a tonal language to learn a toneless language than the other way round. Sanskrit has a complex system of synthetic inflection, which is a rather marked feature, and all speakers of analytic languages would hate your guts for forcing it onto them if you tried to make them learn it. In many ways, Sanskrit is like Ancient Greek. You spend a year learning something that other languages can do without (and do so without muddling the meaning of the text), and even if you learn it, you'll still be doing mistakes quite a lot of the time. Such a language would never have a chance of spreading as an international medium of communication.