I'm using steem.supply on regular basis and see the warning bar on the bottom of my browser consistently and I feel @dragosroua has been absolutely transparent about it.
I actually support his experiment and consider it fair-play. And this is even more so keeping in mind that there is not a way to opt-out (which I haven't).
From my point of view, website owners are free to look for ways to monetize their websites and since this is not done in a resource intensive way, I think it's a interesting and viable alternative to experiment with. Keep in mind that even with the miner scripts, steem.supply remains one of the lighter websites you are probably opening in your browser and there are often banner ads and pretty always video ads that are using much more of your CPU power and bandwidth.
I'm not saying that crypo-mining is always acceptible, but my honest opinion is that it was done in a way that was transparent enough and congnisent enough of the load the webiste creates for it to be totally fine in my book. And this was the case before the opt-out option which I believe should solve any worries anybody might have.
I think it's important to note that @dragosroua has indeed been transparent about this and to me he is by no means an abuser of the steem platform, but a regular and valuable contributor.