There is no question people were trying related approaches in the past (as the paper cites!). Indeed, it's exceedingly rare to find a totally new idea; we always stand on the shoulders of giants, which include but is not limited to Steels's work. The goal, both here and in general, is to go beyond previous work — in the case of this work, to use modern DL tools to learn a more sophisticated language that has a real degree of compositionality and grounding. The hope is that by pushing this approach to its logical limit, we'll get agents that can really understand language, both artificial and natural.