It definitely can take time away that could be spent on the next build, but it's natural to want to take every effort to salvage all the work you've put in. I think that instinct lessens with each bow that gets built, as skills increase and build times get shorter. I would wager that even the best builders have a failure that's hard to let go from time to time.
Also some of the fix it tricks require more skill and attention than the build itself. In the end, it's all useful experience.