Tinder-Quik lights with a spark while wet? I don't think anybody here means that. I think you mean it lights from a flame while wet. If we already have a flame going, then Tinder-Quik is to be compared to other fuels/kindlings, not other tinders.

The same goes with inner tube, which is sometimes referred to as waterproof tinder. That's inaccurate! It may be waterproof "fuel", but it's not waterproof tinder. In fact, I say inner tube is never to be considered tinder. Try to start a dry inner tube by using a ferro rod, and let me know how it works out. If something can only ignite from a flame (and not from a spark or another chemical reaction), then that's not tinder.

By the way, we're talking about a product (Tinder-Quik) that is both more expensive and less reliable than other alternatives. In that sense, money does matter. I also imagine a situation where a group leader is teaching a group of 20 people or whatever. The group leader needs to know that they don't need to waste their money on garbage when less expensive, more reliable products are available.