I agree that Americans weren't presented with an outstanding choice but they actually voted for Clinton, by about 3M votes. It's only the stupidity of your electoral system (ours isn't perfect either, by a long shot) that got him to the White House.
You really don't understand US political system. Voters vote to send people to Electoral College to vote for a Presidential candidate. Doesn't really matter whether a candidate wins by 1 vote in each of the 30 states that voted for Trump but voted in Millions more for Clinton. At least in US you know you are voting for a President.
In UK you are voting for an MP only. This MP may vote for a PM candidate but they may abstain and vote for nobody. There is no requirement to vote for anything or even attend Parliment.
In US 46% of the people who voted did so for Trump, in UK 37% vote for Tory MPs.