Reinstalling all your programs is definitely the most time-consuming part of reinstalling Windows or whatever OS you are using; without a doubt! And a nice, easy way to automatically reinstall those programs seems like a great tool. I wonder though how much difficulty is involved regarding version changes, settings changes, etc. I would guess that many of the programs you have set to be reinstalled have had newer versions installed since you recorded the reinstallation app, plus in my case no doubt many of the programs that are installed at the time of recording are no longer installed by the time you need to reinstall the OS.
Could be more of a confusing mess than just reinstalling them all manually! Also, after reinstalling Windows is the time that I carefully reconsider just what programs I do and do not want installed anymore. If all your previously installed programs are automatically reinstalled you would have to then uninstall all of those. Could be more messy than I'd want!