... but not expansion teams

(just joking, well, kind of...)
The deal with retail stores, besides worrying about market saturation and targeting customer types is that you have to deal with real estate companies and mall management. There's all kinds of wheeling and dealing that goes on to get pieces of property and then there's no guarantee that you'll get the one property before another (there could be issues with new malls or prior tenants, etc..)
For instance, if you want to move into a Simon Mall (largest private owner of retail property in America) say in Los Angeles, you may have to negotiate opening in one of their malls in ShortHills,NJ and one in Aventura, FL. Then there's no guarantee that you'll even get to move in and open the LA property before the Short Hills property (even though that's the one you really want), however Simon Malls needs to fill out and encourage other companies into their Short Hills complex and are looking to use your brand to hook others. It goes on and on like this and you end up looking at 60 properties to open up only 3 or 4 stores (and maybe forced to deal with market saturation and just hope you can back out of the deal later based on contracted per sq ft amounts not being met in a year)
International stores are harder because of distribution channels and understanding the local markets. Even if Apple is available in Europe, their infrastructure may not be able to meet the demands for a retail store (and by the way, opening a single retail store internationally is much harder than opening five.) Accounting alone can require a much larger overhead than a company will see in return for dealing with each country's policies and amazingly enough, in this day and age, timezones can be a big problem. It goes on and on like that (until you are about to tear your hair out)....
To give you an idea in difficulties, for one company, it took me 3 years to get a single store open in Japan (in the end I ended up negotiating the opening of 3 stores to make it happen), 5 years to get a store in London (though stores in Italy, Paris, and the Netherlands were easy to set up after London in 2 years following) and during that time, 30+ retail stores were being set up in the US
per year.
I completely understand Apple's growing pains in the Retail market, though I can see how to consumers it looks like a poor strategy.