It is way too simplistic to say that colonization is always bad. Viz that Monty Python sketch about the Romans.
India was united by the actions of the English.
I'll never forget a talk by a Hawaiian of Polynesian extraction at the Bishop Museum who was no fan of the Christian colonizers who mandated that Hawaiians give up the sexually expressive sides of their cultures, but said on balance it was worth it because they brought the written word (maybe she meant written Word).

I do not feel that justifies anything, but pretty much every culture that COULD colonize, DID colonize, from earliest times. One possible exception might be the Chinese, who we know had a strong, vital, technical and literate culture thousands of years ago, and did not extend it beyond their continental territory.

But they appear to be making up for it, now.