I completely agree with you in this example. But please note a difference. Your general disagreement with unions is not, I presume, on moral grounds but merely political. They pursue their own interests and (at least nowadays) go too far, often ruining the goose that lays the golden eggs. Conservatives oppose that for the sake of balance and fairness. No deep moral principles, as far as I can see, are involved here. ACLU is more problematic, of course, but can still be accepted as an ally if in a particular instance, they act from an acceptable position and proceed in an acceptable manner.
None of the above applies to Taibi (his writing is pure unsubstantiated vitriol, aimed at enticing class envy). Finally, you CAN carefully examine the unions' or ACLU's position and then agree with them in a particular instance. In contrast, most people take Taibis sides without sufficient knowledge of facts and finance in general, and level unsubstantiated accusations against myriads of people. I have a problem with that.
FRegards, and enjoy the weekend.