It's like in music, if you know you need to practice more to reach a certain goal. There are pieces I've worked on for a while, and I've memorized them, but do not play them consistently well. With more practice, I will. If I were trying to get hired to play in public, I wouldn't expect to be, because I don't play these pieces as well as other people who are paid to play. I don't see anything wrong with admitting this; it is not wrong to regularly assess one's progress in working towards a goal. The amount charged for services (whether they be musical or technical) is orthogonal to the issue of competence. I hope this makes sense.
A dilemma here is if the marketplace is not strong enough for someone to live off consultant's wages, but there are plenty of (low paying) jobs that require something like obtaining the unique number of cookies. If someone is forced into that role (after difficulty landing such a job, because the criteria for hiring are different), s/he may not be able to keep up "consultant chops" sufficient to get one of the consulting gigs when it comes around. I think part of the problem I have is that it is very difficult to explain this aspect of the computer field to people who aren't in it. People seem to think that one is always as good at something as they ever were, or that they will always be evaluated as such by prospective employers. So they are amazed and puzzled about how difficult it has been for me to find a job. In effect, computer professionals might very well "starve for their art" just like musicians.