I've seen so much of this as a government contracting programmer for the last 10 years. There was only one time I was able to convince a group in a department

I've seen so much of this as a government contracting programmer for the last 10 years. There was only one time I was able to convince a group in a department to go with an existing tool. It was SSIS, and it made sense over creating some giant unmaintainable XML data interchange format between state and federal agencies. The most common reasons are: 1) they are unaware of existing products or how to use them effectively. I remember one client who wanted me to implement a complicated feature to remember their position, sorting, and filtering options in a data table. The need was eliminated when I showed them how to middle click and open the record in a new window. 2) they won't, or can't adapt/slightly modify their internal procedures to fit an existing product. 3) they don't understand what they actually do. So they can't evaluate a COTS solution. (part of your job as a consultant is to figure out how things work and design a solution around it) 4) they have too much money. Rare but I've seen it, gotta drain the budget so nothing is left over. 5) they are doing something genuinely different. 6) policies dictate the technologies they are allowed to use 7) legacy databases and reports must persist into a more modern updated interface