Rapid and bold both make perfect sense to me, honestly. There's no point to using them when you are just high enough for a recipe, of course. They'll most likely just fail. But for a recipe, say 15 to 20 ranks under you, they become very useful.

It's kind of a pain to have hasty hands available all the time because of the way the crafting window is set up, so rapid is nice when you run out of crafted mats and need to throw together a few more (like iron nuggets or cotton yarn). Instead of having a maximum of 20% progress as in a standard synthesis, you can progress up to 30% per synth. The rapid synthesis action animation is also shorter for most crafts.. although for Culinarian it actually seems longer.

Bold is fantastic for making lower ranked items that people request. The maximum progress is lower (allowing more chances to increase quality) and the quality tends to be higher. Yes, there is no quality score that guarantees HQ success, and I'm not even sure that a higher quality necessarily increases the chances of HQ, but it does seem like a higher quality score makes touch ups more likely to yield an HQ result. If they ever adjust the HQ mechanic to make more sense, bold synth will be fantastic exactly as it is.

Both have a higher chance of failure per synthesis, but that seems like an obviously good feature to me. You shouldn't be able to rapid synth or quality synth a recipe that you only just have the expertise to synthesize at all. Grinding out training recipes *absolutely should* be using only standard, wait, and action skills. Bold and rapid should only be for 'old hat' recipes, exactly as they are now.