I really can't understand how anyone can even argue with Irish on this, to some extent - I mean, yes. Everything apart from the visual excess of the movie (which is kind of the underlying point) is pretty sloppily done, although they do manage a few rousing moments near the end of the film. It feels hollow, because it comes from a source material that is inherently hollow and empty, and the two directors have made no effort to expand or even add any kind of emotional weight to anything that was even scantly present, to begin with.
All of the cast do what they can and have fun with it, but - it's just hollow, and weightless. There's the faintest glimmer of emotional resonance near the end as Speed wins the race and we're treated to that great little montage, but that's really about it. You guys can say its simplicity is its charm - but, simplicity can be done well, and especially with a concept like this (wacky road racing, in which there are many really quite good exploitation films out there on the subject from the seventies onward). Here, it just never meshes. It's never cohesive, or self-evident in its construction. The races aren't visceral or involving, or blood-pumping, which at their base is kind of a prerequisite. It's a gloppy mish-mash of colors and half-assed everything else.
To be fair, the visual excess was interesting and well-done. If there is ever a Sonic the Hedgehog film to be done in the style of the Genesis games, they need to look here for visual inspiration. Just - you know, with a better director and everything else behind it.