I’m using Google translate, and quoting accordingly. My apologies if the translation was not very accurate and made me misunderstand things.
I agree that different cultures (not just languages!) sometimes present slightly different description in Wikipedia. But we (OSM) use wikipedia/wikidata tags as links to Wikipedia, not as sources. If it was a source, we should use “source:wikipedia” or something similar. When a village X has a wikipedia/wikidata tag, it means “This OSM object has a corresponding page in Wikipedia, so you may want to read-up about it there”. Moreover, any data consumer who may wish to show Wikipedia page to a user would ignore the language you specify - because most users would want to read Wikipedia article in their language, and they will simply use Wikidata to lookup that page in another language. Also, this sounds very theoretical. Have you actually seen any problems like this? How substantial is this problem?
I am concerned that you might be seriously offending people with this statement. Most people participating in OSM discussion care deeply about OSM. Please don’t accuse just because you don’t like the position of others, this is very inappropriate. I myself have met some of the active proponents of using Wikidata at OSM conferences.
This is true that each language in Wikipedia, as well as Wikidata, have different set of rules. Google Translate amusingly translated your expression as “gets a wet rubbish around database rights”, and I take it to mean that Wikipedia simply ignores the laws. I don’t think this is accurate - Wikipedia has a large number of very diligent lawyers who might have a somewhat different interpretation of the laws, especially in how they relate to US, and the community is extremely careful with the copyright law. But again, this is irrelevant. We are not copying data from Wikipedia or Wikidata. We are discussing linking to it.
If I, as a user, want to read more about a place, I will click on the link to Wikipedia. If I don’t care, I ignore it. This is identical to a “url” or “website” tag. We are not discussing if the content of that site is violating database right or has other issues, right?
I think you are exaggerating. This whole thing started after I added a few thousand wikidata tags to the objects that already had wikipedia tags. Same way as iD editor did it automatically for hundreds of thousands, often without any oversight. The number of wikidata tags in the past few years have been used for all sorts of things, there is no new development. You could say it has reached critical mass and enough people started noticing it. But you don’t have to use them - noone is removing “brand”, or “subject”, or any other tags. These are additional tags - for those who need them - and again, there are a lot of data consumers who really do want them.
To answer your question - if someone creates another such project - great. But I seriously doubt it will happen. Google had a similar project called Freebase for a while, and with all their resources, they gave up - and moved all their data to Wikidata. For a very simple reason - it is very easy for a few developers to create a new project. It is extremely hard to build a large community around it, especially when something similar already exists and has a huge community and resources. But regardless - if someone creates it, and people find it useful, i see no problem for community to start adding new tags. Who am I to tell others what new information they should or shouldn’t add?