I said 6-7 years of engineering effort not development cycle which are often linear. I am not blaming for taking long to get things right. If authors think they need more time then of course they need more time. Right now they really want to have broader industry usage and this can't be any clearer when they say:
"Production use measures our design success; it's the ultimate reality check. Rust takes a unique stance on a number of tradeoffs, which we believe to position it well for writing fast and reliable software. The real test of those beliefs is people using Rust to build large, production systems, on which they're betting time and money."
"Production use measures our design success; it's the ultimate reality check. Rust takes a unique stance on a number of tradeoffs, which we believe to position it well for writing fast and reliable software. The real test of those beliefs is people using Rust to build large, production systems, on which they're betting time and money."