Quite agree. The whole concept revolves around a fast reaction adaptable platform. Increasing the standard weapons simply detracts from the weight available for the modules.You can't really up armor the LCS. To do so would basically make it a new ship. As it is I don't think it can take anything over a 76mm without some serious redesign. Hull just couldn't take say a 5 in gun mount like on the burkes and such.
If they want to up armor and up gun the LCS they would have a frigate. So better to just use the LCS knowledge and lessons to build a frigate from near scratch then.
Different gun mounts will have a significant impact on structure not just from stiffening for recoil forces but also the deck penetrations and underdeck structure is quite different. A 76mm may have less impact compared to a larger mount but the structures is going to change. I suspect it would be quite a challenge to alter an existing LCS2 hull to take the mount. For future hulls ......... maybe, but there will be a weight penalty.
As I have noted before the adaptable platform works for the USN but I am not sure if the fan mail really understand the limitations if you try to use it/adapt it as a GP frigate.
I can see how the concept would evolve for specific operating requirements (i.e the Israeli defence force....... who have a long history of capable lightweight vessels focused on their needs ........., or the gulf) but where range, persistence and a true multi-purpose role is desired then it really os not an option.