I simply think that Universal is not willing to spend big money on the marketing for this, as they probably know this won't hit big.
And so far, Downey Jr. hasn't impressed me with his vanity projects and own productions. "The Judge" was mediocre and I get that David Dobkin is a friend of his, but I don't think he was the right choice for the material.
And this movie strikes me as odd, as well, and it doesn't help that Chris McKay and Jonathan Liebesman had to step in to retool the picture.
I'd rather see him take on interesting offers. Who knows, he might get better at producing, but too many stars have shown that they're better off when the movie's in someone else's hands and they can focus on the acting (Will Smith comes to mind, whose got career got increasingly worse as he started producing).