It doesn't sound selfish at all
I'm just thankful that people will build roms because I dont have the resources or time to learn it myself.
The amount of skill and learning depends on your method of building it.
Most of my roms were built by messing around with previously built roms, just copy files in and out of the zip and re-sign it. Most Froyo roms were built that way. This method can be as simple or difficult as you decide to make it.
Building IHO isn't hard, it's learning how to modify it and get the build to start that is difficult, but there is nothing to stop you from building a stock IHO build and then using the previously mentioned method, which is exactly how Harmonia is built these days using a Mrg666 generic IHO build.
Time in another variable.
Adding or removing an app or two is quick and easy, 2 minutes, including re-signing. The deeper you go, the longer it takes and the more trouble shooting it requires.
All of that often pales in comparison to the amount of time you spend supporting others using it.