Hot or Cold

This is the sink in our bathroom in our flat. It looks like a normal facet, even by American standards, but looks can be very deceiving. Here in the UK, plumbing standards as a whole are not quite what we have come to enjoy in the states (this might be because the cities and water systems are so old). For example, showers have an electronic pumping system to maintain water flow (are the systems not already pressurized in the delivery?) and sinks normally have hot and cold water in completely different facets (no mixing like in the states). I think the reason for the separate hot and cold is because it was normal UK culture to just plug a sink and use the water that has/ is accumulating in the basin (like a bath tub). This procedure is fine if you want to soak dishes or hand wash clothing, but wastes water and takes too much time for simple hand washing so most people do not do this anymore. So my question is this, if culture has changed and plumbing fixtures have been updated (to American standards), why does my modern (~5 years old) sink not mix hot and cold water!