The "slows progress" part has some bits of truth in it. This is coming from a from-young bilingual chinese/english speaker. Chinese is harder to learn, ceteris paribus, all other things being equal (especially regarding exposure).

English has 26 characters you can put in a buttoned keyboard. You recurse upon these letters to create new words & meanings. Chinese has what, a thousand? And you'd have to create a stroke system first if you don't have hanyu pinyin. Recursing Chinese characters has problems too, the chinese word for 'good', when split to it's sub-characters represent different meanings.

There were also some Chinese historians that specifically pointed out the chinese language was part of the cause of their worst slices of history despite the chinese having invented gunpowder and whatnot first. They also noted chinese was confined to the elite, who made the language even more complex (in contrast to other civilizations), during certain dynastic periods. Today, the chinese government are trying to simplify the language.

I get that there is pride in people's native languages, but they'll repeat the same mistakes if they don't recognize the weaknesses. It's a bitter pill to swallow.