Yes, fully agree with you. I try to put thought into my posts, and it is annoying to see spam get rewarded...
However, there is nothing that can be done if the witnesses don't do anything. Best course for me, is write well and ignore the spam. Just don't look at the trending.
There is something to do, in fact there are a few.
These things aren't much. But together we can do some good
I think the reporting is a good idea, as is voting for a good witness.
However, I think the downvoting is a futile cause. Similar to the "war" on Haejin, it doesn't really fix the problem. It just pushes the problem under until you stop looking and then there it is again! It really is a structural problem that needs a proper fix.