I did. You just didn't like their costs. Which is reasonable. They do have costs. I just happen to think they are worth it.
For analysis, it increases review time and increases the burden on contributors. The extent to which any one person can review all analyses isn't clear to me, and they would likely need to rely on contributors to self regulate them. But I would expect the maintainers to review them for some minimal level of quality. Being more specific than this would require a more thorough proposal. Given my time constraints and how much I dislike interacting with you, it's not something I can do right now.
As for increasing contributor barriers, yes, adding an analysis requirement would do that. However, I think you could compensate for that partially by reducing existing barriers. I've submitted code to your game before, and I'm unlikely to ever do it again. One reason is that interacting with you was unpleasant for me. But I found the interface difficult to navigate (that has since changed) and the rules difficult to discover. I think barriers could be reduced by switching to github (one of the reasons I use github) with more automated checks on submissions and better documented rules. (At the time when I worked on a submission it was unclear for example how to submit a Rust program that used external crates.)
Invariably though, providing an analysis is still more work. IMO, I think it would add rnough value to be worth it. I imagine many amalyses would build on top of others, similar to how code submissions do that today. As can be seen in any thread about the Benchmark Game, there are tons of comments that misunderstand things or make wild guesses. (Followed up invariably a day later with coy quips from you.) Some of those comments are from people that are unlikely to be helped by my analysis idea. But a lot aren't. I think a lot of people would benefit from an explanation of the performance characteristics of the program.
I generally try not to publish benchmarks without analysis. Here's one example.[1] I care a lot about it and I think it has immense benefits in terms of educating others. But reasonable people can disagree. You might have different values than me, which influences whether my suggestions are applicable to you or not.
As for the disclaimer, I don't really see the point of being more specific. There isn't much to this one? A simple suggestion might be to put it at the top of each page or even in the description of each benchmark. I don't know how much this would help things. Maybe people would still just ignore it.
People regularly misinterpret benchmarks and especially those in your Benchmark Game. From what I can tell, you as the maintainer have done very little to address that. Maybe you don't care. Maybe you think it isn't your problem to solve. Maybe you think it can't be solved or even improved, and therefore it isn't worth doing anything. I don't know. We might just disagree, which is fine.
Invariably, you can just respond and tell me to go do it. I think that's a cheap response, but I know you're fond of it. I've been thinking a lot about it and considering starting my own benchmark. But it will likely be a few years before I'll get to it. It is a trying daunting amount of work.
[1] - https://blog.burntsushi.net/ripgrep/