Because any effort you put into the tone is wasted, and better spent on making it go faster. If it sounds great then wonderful, but keeping it quiet is more important unless you're going racing. Track days are already getting restricted by too much noise, no need to help the NIMBYs out and do their jobs for them.
96dB is a reasonable target, you'll probably get that with just dropping a Cobra or Scorpion exhaust on I reckon. Removing the cats will make it A LOT louder, and it'll also sound raspy and horrid. As it's not going to be a track car at all for another year at least, I'd stick to something like that. Spend the extra on a set of R888Rs for the track