As a Canadian, I have a similar stance: the US stock market provides enough intl diversification.

Canada has a lot of resource companies which largely follow the global economy.

Most big corps have less than half of their sales in US.

Developed markets still pay with a visa/MasterCard and have iphones. Or the US owns a stake in their local equivalent. Or Amazon is expanding there.

Truly emerging markets barely have a stock market, but their citizens probably eye a Coca Cola, have an intel PC and an android phone doing searches on Google.

There's a potential tax advantage in splitting into different holdings. If you need money you can sell the one that hasn't gone up thus delaying or avoiding capital gains tax.