There are a few things that cabin crew, and pilots can see as common ground, but not many. We come into the industry very different backgrounds. Pilots are highly educated, highly skilled, and professionally qualified whereas cabin crew have lower levels of education, and there's is not a profession (although most behave in a professional manner). Otherwise there are quite alot of differences. For example salary. If flight deck opt to defer a pay deal, or take a pay freeze they don't lose out as much as cabin crew. A pilot's finances are probably not quite as finely balanced as a stewardess's with the co-pilot earning in a low cost jet airline something in the region of £45k, and the cabin crew earning something in the region of £15k (which would include bar takings and so on). We have different FTLs, and very different contracts. Some airlines have very different rostering rules for the two groups. All in all the groups are too disparate to be represented successfully by one union, and the law prohibits coordinated action between two unions.