Unions are useful as long as they refrain from advancing their cause unfairly at the account of others. While BA uses 11 B777 CC where legal requirements are 8 and the union demands 12 during times of financial aviation trouble, that union is working against the well being of that airline, the aviation business and the general public.
I therefore caution anyone of forming, participating in or supporting strong unions, we know all about human nature, which has a long track record.
I worked once in a large world-known private company, which prohibited unionizing of its employees. The company was in good position as industry leader, and more than 15 qualifying applications for each vacancy. They are right. Don't like working there, go elswhere. Without unions, the UK, the US car industry as examples and their workforces would have been much better off, financially and in any other way. Any worker strikes lately in Japan Airlines, MALEV, Czech Airlines, Danube Wings, to name a few?