"There is no need for the production of more works of art [...] Aesthetic information as such is interesting only for the rich and the ruling. [...] Thus, the interest in computers and art should be the investigation of aesthetic information as part of the investigation of communication. This investigation should be directed by the needs of the people. [...] We should be interested in producing a film on, say, the distribution of wealth. Such a film is interesting because of its content; the interest in the content is enhanced by an aesthetically satisfying presentation."
That is: to the author, the purpose of art is simply to enhance the presentation of something whose primary purpose is political.
It may be that the author's position isn't specifically about politics as such: he might say, rather, that art should be subordinate to morals, that making art is only valuable in so far as it furthers some other goal that has value in itself, which might or might not be political. But the specific examples in this article are political.
The author does evidently have some other more specific reasons for being skeptical about "computer art". He says that "the repertoire of results of aesthetic behaviour has not been changed by the use of computers" (which might be true, or might be false now but have been true in 1971, but he offers no evidence or arguments for it). He says that "outsiders from technology" are invading the art world without understanding its political situation and "surrendering to the given 'laws of the market'" rather than rebelling against commercialism as real artists should. He says that technology in general, and computers in particular, worsen "the alienation of the artist from his product". Two of these reasons are also political but do engage with the specifics of "computer art" as such. But I think his main reason is the overarching super-general political one: there should be no computer art, because there should be no art as such, because there should only be anti-capitalist political activism which will sometimes use art as a tool.
So far as I can tell, the guts of this argument -- art, in practice, is driven by the rich and powerful, artists should reject this and focus on serving the greater need to overthrow the system with those rich and powerful people at the top and replace it with something fairer, therefore such-and-such an idea in art-as-such is a distraction -- could be transplanted without loss to any moment in the history of art and any particular artistic idea or technique or movement.
Maybe that or something like it is right, but my bet is that in practice the human race is enriched by having some people in it who create art because they love creating art, for whom other concerns are secondary.
(Having said all of which, so far as I can tell the author is basically correct about "computer art" not having contributed much aesthetically, and if he'd written more about that it could have been very interesting. And he might be correct about technology increasing the separation between artists and what they produce, and about that being a bad thing, and if he'd written more about that it could also have been interesting.)