I see this phrase used a lot, and always thought it to be incorrect, but I see more and more people using it so I'd like to find out if I am wrong or not.
As an example the following sentences:
The samples were unable to be collected.
Sampling was unable to be performed.
It seems to me that the subject here are the samples or the sampling, therefore it is incorrect to use "unable to be" when they are describing an action that was to be done by someone else.
I would rather say one of the following
We were unable to perform the sampling.
We were unable to collect the samples.
The samples could not be collected.
The sampling could not be performed.
Do these last two have the same meaning?