Perhaps the biggest problem with ITAR is represented by the counter argument, what we don’t do because our hands are tied, others will and profit by it.
For example, if I can’t put an open source LH2/LOX propulsion system on the internet for fear of conflicting with ITAR, then those who can in the rest of the world will profit from the development while I won’t.
Sure, I can do my own thing in private. But my results will be bounded to about ten or twenty percent with my capabilities tied up in this way — because I won’t be able to work with others in a natural way and will have too much invested in not producing, not sharing and not excelling in the endeavor.
This is just an example, of course. No immediate plans for a cryogenic hybrid aerospike engine, or anything like that.