The clearest definition of a "renewable resource" in Minecraft terms that I've heard is one that can be produced in any indefinite quantity given infinite time, but finite space. Equivalently, wall off an arbitrarily large area of a random world from bedrock to skybox, use any resources in it you like, and give me one of whatever block/item every week from now until the heat death of the universe.
This allows things like iron in Vanilla (place your bounding box such that it contains a village that you could use to spawn iron golems), virtually any ore or metal in the presence of MFR's laser drill or Ex Nihilo's sieve, and things like high-tier Chromaticraft stuff that can take a great deal of exploring to get the info fragments and pylons for, but can thereafter be produced from otherwise renewable resources (assuming you have a renewable way to get crystals, ChC dusts, elemental stones, etc.). However, it does not include things that can only be found by indefinite exploration, such as iron ore blocks in Vanilla or nodes in vanilla TC. No matter how large an area you quarry, you'll eventually run out of whatever you were looking for.
It's not semantics, it's merely an attempt to use words in a meaningful way. We use the term "renewable" to refer to resources that you don't have to keep on expanding your worldgen to get more of. Things that can be renewed within a closed system. Saying "everything (except End Stone and End Portal Blocks) is renewable because worldgen" is not a useful statement, all semantics aside. It's not the basis for an interesting discussion.
Given that some people are interested in the challenge of producing unlimited resources with a closed system, we need a word to describe such a distinction. What word would you suggest, if "renewable" is not suitable in your view?
This.