I have made two calibrations, one in a narrow space (normal place of the bl5) and the last in the same room but with 5 meters of space all around and in front of my bay window completely open.
I placed them again into their place and the sound was far less thin.
In order to make some modifications of my set up I had to push them nearly again the wall and they again sound thin.
They absolutely need a minimum space around them, that's an evidence.
There will be always people complaining about the quality of a speaker because of their taste, bad ears or simply because they don't respect or misuse their speakers.
If their beolab 5 are in perfect working order and well calibrated and they are still unsatisfied, WOW, I am very sad for them.
The beolab 5 is probably not the audiophile Holy Grail speaker but would certainly be accepted into the room of the Knight's Round Table.
Anyone insatifsied with a pair at 5000 euros please send me a pm 😁