well, yes: afaik, Pd lacks an API for state-saving (btw: like any other programming language i know)
in the sense that persistence isnt tighly-coupled? almost every (decent modern scripting) language provides a way to get at the state of an object. and usually query it for all the types of messages it responds to, the names of its instance methods, attribute accessors, etc.
as an example. making Toxy objects, it became incredibly pedantic since there was no way to do this. one option was forward _every_ message that passed to an object, and attempt to infer its type from TCL, eg "ok, a list of 3 floats, lets try the vector editor". another was to read thru the help file, and source code (since the class-rowser is MIA). or merely implement a few features piecemeal. an automatic 'inspector' that works on any object, and prepopulates widgets based on metadata hints is pretty much impossible.
thats why i'm excited about LV2. finally useful metadata. not to mention 64bit compatibility, and GUI agnosticity :)