Well maybe you are right, or partially right... I only wanted to point out that even if Tourism is working like that now, you can't really "feel" it, you can't really feel a significant difference. Most of us agree that Tourism income is too high overall. Right now it feels that Wealth and Tourism are both based on mixed factors what they also share.
For example Trading is easy to recognize, because it is mostly distance related and you need Freighters in space to establish them. So it is a third type of income where you make an active effort to include it into your economy boost. Tourism is just floating around and is free. So I meant to actively build many many improvements to increase Tourism values, while overall it should be weaker. I was talking about peaks, about more of the extremes. Very very low and very very high Tourism rates for a given planet - that you coordinate.
Lets say for example a level 4 planet, boring, deserted, located in no mans land, has not much population, good for almost like only mining operations. - So a planet like this should have almost zero Tourism. (except if it is an Influence wonder)
While a planet that is thriving, has all bunch of nice stuff should have higher tourism rates. I mean very very high here. And a lot more if you up its Influence.
So overall, tourism should offer 80% less than it offers now, but you could make it so that you improve upon Tourism strongly by increasing Influence, Approval etc. So at a given planet your income may almost entirely be Tourism based. On other planets only market based. So Tourism should be a more playable area, more of an option, a choice you make to strengthen it or leave it out of sight. I would really like to see it more as a distinguishable factor. I hope you get it what I meant to say.