There was little enthusiasm for .uk before the launch so the slow adoption now was all fairly predictable. Joe Public didn't care either way and wasn't consulted anyway. The domain community were overwhelmingly against it. Nominet were the main ones pushing for .uk and wouldn't take no for an answer. The cartel of big registrars who are the only members Nominet needs to listen to as they have a de facto "controlling interest" had nothing to lose and the possibility of gains down the line so were happy to go along with it. Nominet know that even if no sites switch to .uk, 5 years down the line the owners of all the good names will be paying double the reg fees to protect their .co.uk domains' .uk counterparts so they'll get a guaranteed increase in revenue.