Oh, is this what you guys have been building for three years? I can build it in a month!
Substitute the two time durations with something appropriate and you end up with how some software developers react after encountering a new project or application. I have seen this happen in multiple situations, where I had more context of how the application in question had evolved which the person making the comment did not have.
I have wondered why people make this comment that at times I felt showed a lack of respect to the thinking and doing that the developers of the application put in. I think I now understand why. The comment is not necessarily on the relative abilities of the team that built the app and the person making the comment.
When a person makes this comment, they are making a judgment on the current state of the application and their ability to build it in a particular amount of time. What they don’t see and factor in is the amount of thinking, debating, iterating and mistakes that went in to taking the application from an idea to it’s current state. Effectively the comment is on the perceived time required to build a snapshot of the application and ignores the accrued knowledge and skill that resulted in the current snapshot. This knowledge would not have been crystallized without the team going through the process of building, making mistakes, fixing and improving.
In other words, the person making the comment can theoretically build the application in the time they claim because the team did all the thinking and the current state of the application is a specification for exactly what to build. But that specification took time to evolve, which is a side effect of the team’s work.