The word has negative connotations, but I stand by it. I an not saying there result isn't stronger, but if you extend cultural mixing out to the maximum - say humans and the planet survives another thousand years, and global travel is no harder than traveling to the next town over - what you end up with is homogeneity, and this would be sad, I think. Imagine it: the entire world speaking some pidgin derivative mashup of Mandarin, English, and Hindi, with essentially the same culture everywhere on the planet. Just as has already happened, languages are lost, because nobody speaks them natively anymore. All that's left of the original cultures are some UNESCO sites and preserved old movies. I can't say the world wouldn't be stronger for it, but in the process, something irrecoverable is lost.