Even though the concern these recruiters are expressing is valid, this is a very weird question and sounds like a bit of a red flag.

One part of this should indeed be you as an employee being prepared to put in the time, effort, eagerness to learn, etc. Another part however should be what incentives they are able to offer you in order to make you stay.

This could be

• Opportunities to learn
• A productive work environment
• A healthy work culture
• A strong team to be a part of
• etc...

This is what my answer (and counter-question to them) would be.

Depending on the type of work or location this might vary though.

Edit: Obviously if you have been employed previously for any amount of time, that could also be part of the answer.

Even though the concern these recruiters are expressing is valid, this is a very weird question and sounds like a bit of a red flag.

One part of this should indeed be you as an employee being prepared to put in the time, effort, eagerness to learn, etc.  
Another part however should be what incentives they are able to offer you in order to make you stay.

This could be

Opportunities to learn

• A productive work environment
• A healthy work culture
• A strong team to be a part of
• etc...

This is what my answer (and counter-question to them) would be.

Depending on the type of work or location this might vary though.

Edit: Obviously if you have been employed previously for any amount of time, that could also be part of the answer.