Often in political debates the Founding Fathers intentions are cited, isn't it explicit in the Constitution?

My impression is that the Constitution is written loosely, showing how the gov’t will be run, not who or how conservative or liberal. I assume many biographies have been read. I’d like to think the document is their legacy not personal interests. To adapt to the times (insert bashing here) surely they intended this? Someone here may think they know, maybe a historian maybe their direct descendents but it’s arrogant and improper to cite this authority. I’m not saying forget the accomplishment, I’m not saying change the Constitution even if some say many departments of the gov’t, that the document set out rules for and then created, are now Unconstitutional in their eyes, or to stop emmulating or copying their personal stances. I just wonder why they are canonized in some eyes?