Hoi surprise, data can be dirty and we are talking about data not at our end but at the end of Scopus (an organisation that does not care about us) OCLC, VIAF including all the library authorities of this world and ORCID. So it is not bots fail, it is the data fails us.
Now here is something to consider, how can we be the place where authorities come together if we do not take the data warts and all. The desired behaviour is a pipe dream when at the same time you want to accomplish data that is meaningful, worthwhile. Given that you are professional at data (as per your user page) you should understand this well.
As to data cleaning, I merge quite a number of items. For me the key thing is that with more data merged, chances of keeping the data clean improve. The interoperability of data improves.
The notion that we should stay away from datasources is absolutely painful. We have lost years in not accepting data that is/was no beter than the data we have/had. For me the this notion that we can build Wikidata and keep it clean is false.