Productive and Unproductive Labour - Productive Labour As Misfortune?

Productive Labour As Misfortune?

In the first volume of Das Kapital, Marx suggests that productive labour may be a misfortune:

"That labourer alone is productive, who produces surplus-value for the capitalist, and thus works for the valorisation of capital. If we may take an example from outside the sphere of production of material objects, a schoolmaster is a productive labourer when, in addition to belabouring the heads of his scholars, he works like a horse to enrich the school proprietor. That the latter has laid out his capital in a teaching factory, instead of in a sausage factory, does not alter the relation. Hence the notion of a productive labourer implies not merely a relation between work and useful effect, between labourer and product of labour, but also a specific, social relation of production, a relation that has sprung up historically and stamps the labourer as the direct means of creating surplus-value. To be a productive labourer is, therefore, not a piece of luck, but a misfortune."

The idea here seems to be that being capitalistically "productive" effectively means "being exploited," or, at least, being employed to do work under the authority of someone else. Marx never finalised his concept of capitalistically productive labour, but clearly it involved both a technical relation (between work and its useful effect) and a social relation (the economic framework within which it was performed).