Because Marx considered only labor that produced tangible goods such as farming and manufacturing to be valid economically. It's all in Das Kapital, and in many posts here on FR, though Marx is seldom given credit. At least conservatives tend not to subscribe to communal property.
You mean Karl Marx was an advocate for small government?
I guess he wasn't as far off the beaten path as I thought. I've said for a long time that the most critical sectors of the U.S. economy were manufacturing, construction, agriculture, and mining -- based on the same rationale that Marx used.
Even manufacturing is a secondary industry. Mining and agriculture are primary industries. Timber and fishing count as ag.