I think the key here is distinguishing between what we can and can't actually control.
For example, seeing what voucher we would get from a jewelry order wouldn't change the fact that we have no control over how often that specific voucher turns up. If the ratio for vouchers is, for example, 4/3/2/1 from green/blue/purple/gold, the gold voucher is still only turning up 1/10 times, and the times it does turn up it's going to be exciting still.
Same with boats, gold vouchers will turn up at exactly the same rate- and they're actually more exciting this way, because you have the anticipation of filling the boat and knowing there's a good prize at the end.
This adds more strategy too, since the value of the voucher is a known quantity now, and factors into whether the boat is worth it. Normally, I'd send away cream/sugar boats, but if I see there's a gold voucher at the end- I might be more likely to fill it. The randomness is totally in effect still, since I have to wait 4 hours between boats even if I send them away all the time. This won't suddenly create a glut of gold vouchers, but it would reduce a lot of frustration.
The town is a similar story. If bricks only show up 1/20 visitors, that ratio will not change. But if the guy who wants to see beach café/spa/B&B is offering a brick, I might send him through- even though he wants a ton of ♥♥♥♥. Or alternatively, seeing what they want BEFORE they go into a shop- it's still random, you have no control over what they want- you can just see it before you commit to them.
I think people are missing the point between getting rid of the randomness, and making the randomness a little more transparent so you can see what's going to happen before you make a decision. The chests and fishing are absolutely fine, getting materials through your farm needs no change, but boat/truck orders could definitely benefit from the vouchers being transparent IMO, and possibly the town could be a little more transparent too.
To finish with an analogy- what most people are seeing with this idea is a game of poker where you can see ALL the cards (which would be boring as anything). What the game is currently is a game of poker where you can't even see your own cards. I'm recommending opening it up enough so you can see your own cards, giving you a little more control over what's going on whilst keeping the randomness a strong factor.

