I tend to follow the same line of thinking as Josh.
In general, waiting lists represent a degree of security for a maker....meaning that as long as your physically able to work, you can put bread on the table and keep the wolf from the door. We also have many other responsibilities along with the waiting list. We must keep a presence at shows by having knives available, stay active within the knifemaking community, not to mention the responsibilities of everyday life. Generally as sole proprietors.
Waiting lists can also be a source of frustration for makers, if you happen to be dealing with a fickle client, that has too much time to think about what they've ordered. It seems about once a year I wind up taking an order that causes nothing by grief. Its usually obvious that the individual isn't all that savvy about custom/handmade knives, and you deal with this accordingly, however, some are not so easy to spot. The most recent event for me played out like this......
An individual called, and wanted to order a hunter of 52100. We discussed it, and I told the individual the expected waiting time, and quoted a price. All is good....right? Until the next week.... the individual calls and asks if we can change some things, and I say "Of course". So we discuss things, and when I mention that the "upgrade" will increase the price $XXX, the individual wants to know why the price is going up, because I had already quoted a price. I explain the increased costs of materials and time, and again I think things are good. OK, you can see where this is going. To make a long story short, the individual is calling nearly every other day, asking to change this or that about the order, and a simple hunter turns into a San Mai mosaic damascus piece, with VERY specific handle material, and ever detail mapped out. All the while the individual tries to trip me up with "OK, if this costs XX, and this costs XX, then if I do this, how much will it cost...."Whats the cost difference between this and this?" And on and on. All the while I'm doing my best to be as nice as possible, wanting to please the client. Due to the nature of the very specific handle material, which is not easy to locate/procure, I told the individual that things might be delayed until I could locate/procure the handle material he demanded, offered alternatives, but he still demanded it. I put out the "feelers" for the handle material, wait, and keep looking myself. A few months go by, and then out of the blue I get a nasty email from the individual, cursing me, canceling the order, and telling me that since I'm unwilling to fulfill my responsibility to him, he would do his best to ruin me as a knifemaker. In this case, I was really glad that I have a waiting list, because I believe that no matter what I would have done, the individual would have been a problem....likely for a long time after the knife was delivered. I'm sure that most makers who have been around a while have run into similar situations, and if not, consider yourselves blessed. Its very frustrating to invest such a huge amount of time and effort in a customer, only to be badgered the whole time, and cussed at in the end. I'm happy that I had a waiting list....I think it helped prevent a lot of future grief in this case.
The "Good Clients" who allow me to have some leeway in creating their knives (as Josh mentioned), are the ones who get the best pieces, because I really enjoy making them, whereas the ones like I mentioned above, who want to "box me in" get what they order, and nothing more. Not because I intentionally do anything to a lesser degree, but because there just isn't any joy in it.