Par4QC I think it kind of odd, that these fellas would be European captains. They seldom play there, and they've all been living in the U.S. for several years. Just doesn't seem right, for some reason.
It's pretty much inevitable with the changes to world golf over the last 30-40 years - it's much easier now for the best European players to be members of the PGA Tour (which has the highest standards and deepest fields, on average) and still maintain membership of the European/DP World Tour. For the top players in the 1980s and 1990s, the choice was either to play mainly in Europe and only be able to play 6-8 events in the US (including the majors) or commit to being a full member of both tours and have to play something like at least 15 events on both tours, with all of the travelling that this would require. More recently, there are a number of events (majors and WGCs, and maybe a few others) that effectively count towards the membership requirements on both tours, so it's much easier to be a member of both tours. It also means that the balance has shifted the other way - it's now possible to be a member of the European Tour and only play something like 6 or 8 events on that tour (which most guys based in the US get by playing the Middle East events early in the year, the Scottish Open as part of Open Championship preparation and the big European Tour events like the PGA Championship at Wentworth and the season-ending Tour Championship).