After 20 years of building therapeutic relationships between doctors and patients, patients present to the surgery when they need to and the doctors time is spent productively. This is rational, needs based care. It takes a long time to build up relationships with patients, to give them the confidence to manage problems themselves and to work out the best way to use the expertise of the general practice team. This works better with continuity of care, which we are continually trying to improve, but in an urban practice like ours where there is a 30% per year list turnover it is a never-ending task.
A walk-in centre opens up next door, and forced to see 40 patients a day, they try whatever they can to get patients through the door. They are incentivised to see patients as often as possible, rather than help them manage problems themselves. This is the effect of perverse incentives and is typical of market driven healthcare.
Before long patients are popping in to the walk-in centre for second opinions from nurses with a fraction of the experience of the patient’s own GP, with itchy toes, furry tongues, odd smells, and a sore throat that started on the way to work. In short, anything. All that matters for the walk in centre is that the patients, now rebranded as consumers, come in through the door.
A Better NHS 
Just to present the devil’s advocate here:
“patients are popping in to the walk-in centre … [for] itchy toes, furry tongues, odd smells”
Sometimes there are things that patients think are too trivial or even too embarrassing for them to take to their GP, but would prefer to take to someone who does not know them, and who they hope they will not see again in the future.
Similarly, patients may prefer to discretely ask the advice of a pharmacist precisely because they’ve never seen them before, and will never see them again.
Its a good point, but the walk-in centre is a very expensive way of arranging second opinions (which can be important). My experience of walk-in centres is that there are very mixed reasons for patients seeking second opinons ranging from the very serious to the very minor, but compared to a managed appointment system and a patient list, it is much less efficient because so many problems could have been answered over the phone by a doctor who knew them, or even self-managed. Perhaps, the necessity for an anonymous consultation is another danger of overemphasising ‘efficiency’, Nevertheless, I believe patients would, on the whole benefit from more, not less continuity of care and less medicalisation of self-limiting conditions.