I think you are on to something. Lots of giggers will be the first to tell you that all of these shades of gray are pointless for live use. Some even get aggravated when it becomes standard to have the extra stuff on most new offerings, because they never use it, or would prefer just to bypass it altogether. In another response, I mentioned the issue of background noise that is potential to PT2399-based delays, so again - a tone control might be a way to cater to people who use a delay in a specific environment where the noise becomes an issue, but is just basically "snoring in a hurricane" when used on a gig. It could also be simply because "low noise operation" has become a bit of a big deal marketing point. No one likes a noisy pedal, but it's oftentimes not the issue we think it is. If you play single coils that hum, use an old amp with carbon comp plate resistors, have a few beloved old pedals that are kind of hissy or hummy but otherwise just sound great, you probably really don't care. ...IMO, you KNOW you're over-obsessing with rig background noise when the PA is idling with more hiss than your guitar rig is putting out with stuff engaged!