The guilds of Europe often had the backing of a royal letters patent, which *is* government policy. In addition a monopoly is still a restriction on commerce. Some of China's dynasties relied on state-owned monopolies for the bulk of their revenue (including it seems the reigning one), but not the Ming.
"Having the backing" and "being created by" are two different things. The Guild system was not government imposed on the merchants and artisans.
And a small scale monopoly hard to enforce isn't a very effective restriction.
I spoke to one of the most prominent experts in Chinese economic history. He's spent much time dissuading the notion that the Chinese state has always been all powerful.
And this would be who?
I'm not trying to be annoying, but vague statement is vague.
Europe lacked a powerful emperor, yet its religious heritage also constrained the development of capitalism. Otherwise, the Church would not have banned usury among adherents, and then frequently whip up pogroms against the Jews all across Christian Europe. It's stupidly simplistic to blame large trends on one or two easy explanations.
The Church's ban of usury had little effect in the era we're looking at, and I'm not sure how much the Church as an organization whipped up pogroms - the Crusades era ones were at most (in terms of Church involvement) on the level of individual preachers, not commands by authority able to enforce its will.
Plus, having the Jews able to practice it freely (subject to persecution, but in the sense of them not having any such strictures) makes it even more difficult for opposition to usury to be fully effective.
I don't disagree that it's stupidly simplistic to blame large trends on easy explanations - history is complicated - but some states wielded more control than others, some states were more favorable than others, and some organizations more effective at creating certain environments than others.