Well, I do in the sense that it's wish fulfillment to think you could even get an anarchy working. And yeah, it's a hard life they have, but it's clear that it does work, in many ways. Not in all ways, no
OK well to start with there are people (not me) who think anarchism could work. So basically you are saying you politically disagree with the premise of the book, which does not make it wish fulfillment. But the again the point is not merely when it is paradise or not. She is testing the idea to destruction. Start out by assuming an idea works at some level and see where it leads. That is NOT wish fulfillment, especially if the conclusion is 'not very well'.
Incidentally I think a lot people miss the craftsmanship that went to the dispossessed at level other than literary or moral philosophy. One of the things that I think LeGuin was well aware of is that every attempt at managing a complex industrial economy without markets has led to disaster. But LeGuin is trying to test how much freedom is really possible within an economy working on anarchist socialist lines. So to test that she has to make her economy work at some level.
OK but she does not just hand wave away the problem by making everything rose. Instead she puts her imaginary economy under siege, where food has to be produced by sustenance agriculture, where practically nothing is imported or exported, where there are few consumer goods. And so that simplies the economy to where a completely planned economy can work. The U.S. essentially ran as a planned economy in WWII. Give your economy a permanent state of emergency, and that is something a planning process can manage. It is when you seek something beyond bare bones survival that markets (or some equivalent) are needed. Note that Cuba survived for a long as a planned economy under the same circumstance. It did not work well, but a bare bones extremely poor society can manage under a planning regime. In fact such regimes manage emergencies better than capitalist economies the same size. Cuba manages Hurricanes and natural disasters better than the U.S. And that is not to say that the Cuban system is great. (In fact it looks like it may finally come to an end, though it looks to me like it may take the Chinese path of keeping one-party dictatorship, but restoring capitalism). So it is neither wish-fulfillment or even impossible for an "anarchist" society to "work" as some level. (Bear in mind that "anarchism" does not equal "no formal rule making" though in Le Guin's society those rules were enforced by violence, which is why I put "anarchism" in quotes.)