"That worker is productive who performs productive labour, and that labour is productive which directly creates surplus value, i.e. valorises capital.
…
Only the narrow-minded bourgeois, who regards the capitalist form of production as its absolute form, hence as the sole natural form of production, can confuse the question of what are productive labour and productive workers from the standpoint of capital with the question of what productive labour is in general, and can therefore be satisfied with the tautological answer that all that labour is productive which produces, which results in a product, or any kind of use value, which has any result at all.
…
Every productive worker is a wage labourer; but this does not mean that every wage labourer is a productive worker. In all cases where labour is bought in order to be consumed as use value, as a service, and not in order to replace the value of the variable capital as a living factor and to be incorporated into the capitalist production process, this labour is not productive labour, and the wage labourer is not a productive worker. His labour is then consumed on account of its use value, not as positing exchange value, it is consumed unproductively, not productively. The capitalist therefore does not confront labour as a capitalist, as the representative of capital. He exchanges his money for labour as income, not as capital. The consumption of the labour does not constitute M-C-M’, but C-M-C (the last symbol represents the labour, or the service itself). Money functions here only as means of circulation, not as capital.
…
This phenomenon, that with the development of capitalist production all services are converted into wage labour, and all those who perform these services are converted into wage labourers hence that they have this characteristic in common with productive workers, gives even more grounds for confusing the two in that it is a phenomenon which characterises, and is created by, capitalist production itself. On the other hand, it gives the apologists [of capitalism] an opportunity to convert the productive worker, because he is a wage labourer, into a worker who merely exchanges his services (i.e. his labour as a use value) for money. This makes it easy to pass over in silence the differentia specifica of this “productive worker”, and of capitalist production — as the production of surplus value, as the process of the self-valorisation of capital, which incorporates living labour as merely its AGENCY. A soldier is a wage labourer, a mercenary, but he is not for that reason a productive worker."
Marx had choice words for those who confuse productive and unproductive labor.
https://www.marxists.org/archive/marx/works/1864/economic/ch02b.htm
"That worker is productive who performs productive labour, and that labour is productive which directly creates surplus value, i.e. valorises capital.
…
Only the narrow-minded bourgeois, who regards the capitalist form of production as its absolute form, hence as the sole natural form of production, can confuse the question of what are productive labour and productive workers from the standpoint of capital with the question of what productive labour is in general, and can therefore be satisfied with the tautological answer that all that labour is productive which produces, which results in a product, or any kind of use value, which has any result at all.
…
Every productive worker is a wage labourer; but this does not mean that every wage labourer is a productive worker. In all cases where labour is bought in order to be consumed as use value, as a service, and not in order to replace the value of the variable capital as a living factor and to be incorporated into the capitalist production process, this labour is not productive labour, and the wage labourer is not a productive worker. His labour is then consumed on account of its use value, not as positing exchange value, it is consumed unproductively, not productively. The capitalist therefore does not confront labour as a capitalist, as the representative of capital. He exchanges his money for labour as income, not as capital. The consumption of the labour does not constitute M-C-M’, but C-M-C (the last symbol represents the labour, or the service itself). Money functions here only as means of circulation, not as capital.
… This phenomenon, that with the development of capitalist production all services are converted into wage labour, and all those who perform these services are converted into wage labourers hence that they have this characteristic in common with productive workers, gives even more grounds for confusing the two in that it is a phenomenon which characterises, and is created by, capitalist production itself. On the other hand, it gives the apologists [of capitalism] an opportunity to convert the productive worker, because he is a wage labourer, into a worker who merely exchanges his services (i.e. his labour as a use value) for money. This makes it easy to pass over in silence the differentia specifica of this “productive worker”, and of capitalist production — as the production of surplus value, as the process of the self-valorisation of capital, which incorporates living labour as merely its AGENCY. A soldier is a wage labourer, a mercenary, but he is not for that reason a productive worker."