The point is that you cannot copy data from other sources if you have not been given permission to do so. If you know a hotel exists because you personally have been there, or because you can see it from properly licensed imagery, or because it's in a properly licensed database, then you can add it, but if you are finding hotels by searching a website that did not give you permission to use the search results for OSM, that is not allowed (and makes mapping harder for everyone else).

See the wiki: https://wiki.openstreetmap.org/wiki/Copyright#Proprietary_data

Just as importantly, if the DWG reverts your edits, and you have not gotten permission from them to undo that revert, you cannot just decide they were wrong and do it anyway. That's a good way to get banned.