I couldn't agree more.
If this is the case then we could try going for them under article 10, preventative and protective measures. Basically saying there are not enough protective measures for the persons that are unable to be moved. Even under the good old simple 5 step risk assessment method, dealing with remaining risks, this should identify the measures needed to protect the relevant persons and if compartmentation addresses this risk and is 'reasonably practicable' then compartmentation it is.
Another argument is, the building needs to be able to support firefighters who may be rescuing relevant persons.
I was originally really just considering office/factory/shop type of risks.
Each case on its own merit.

(There's also the much overlooked article 8, which links in with article 4(1)(a) "Measures to reduce the risk of fire on the premises and the risk of spread of fire on the premises", for some reason I tend to look at article 9 onwards, possibly because article 8 is not even on the audit form.)