Issue Tracking Software vs. developing your own in house Issue Tracking

I often consult with clients on a regular basis, and am frequently asked, “Should I develop my own in-house issue tracking tool?”
Seldom will you end up with an in house tool that is as full-featured as an already established product. External issue tracking systems benefit from being refined, debugged and optimized from the feedback of thousands of users. The user experience is much better, which allows you to solve the issues faster.
Developing an in house Issue Tracking tool is also much more expensive than purchasing one. Don’t you prefer that your highly paid team spend their valuable time developing the company’s products rather than an Issue Tracking application? It is much more effective to have them focus on their job and have someone else take care of the Issue Tracking tool for a fraction of the cost.
In a sense, it is similar to how you prefer to hire a company to clean your office rather than asking your developers. They might be very tidy, but you probably still prefer that they focus their efforts on developing software rather than throwing away the trash or mopping the floor.