This is intentional. It's a tough problem to solve since 98% of users can't figure out how to get to their local site and type Google.com when .co.uk or .de would give better results. From Google's perspective, 98% of people get localized content (which is a good thing) and the other 2% can use techniques like the above to get to the general google.com search box. They should indeed make it easier, but that's the price you pay for a very basic homepage. It's hard to add lots of options without making it cluttered.