Your basic errors were:

Performing an undocumented mechanical edit (the text at https://wiki.openstreetmap.org/wiki/Mechanical_Edits/Mateusz_Konieczny_-_bot_account/fixing_malformed_shop_tags does not cover this case).

Thinking that changing "rare tag I do not understand" into "common but meaningless tag" added any value.

Continuing with these ridiculous edits despite being told that they were damaging (and after you yourself had reverted previous examples after previous complaints!).

Not using any common sense when trying to work out what a sensible value might be. Did you ask anyone? No.  Did you investigate? No (a search locally for shops with the name Lighthouse will find a number of "Lighthouse Charity Shop" examples).

I can guarantee that a mention on IRC that you were going to change a shop in Nottingham with the name Lighthouse into a nondescriptive value would have got an immediate response.
