( for more on this topic see
http://www.flyertalk.com/forum/showthread.php?t=580011 )
I think it depends on the airline. For example, during their 'welcome message' over the PA, United's FAs make it *very* clear that they're there 'for your safety' and to 'assist you in an emergency' - Everything else is secondary and their attitude makes that clear. I've seen them snap at pax who have pushed the call button to ask for a drink or pillow.
However, on a more customer-oriented oriented (and, coincidentally non-union) airline like WestJet I probably wouldn't have a probem pushing the button as they're more 'VFR'-oriented ('visiting friends and relatives') and don't cater to business travellers as much. Southwest may be the same - I'm not sure as I've never flown them.
I've also seem similar cultural differences between Lufthansa and British Airways, i.e. I wouldn't push the button on LH but would on BA (however, that may have changed, as I haven't flown BA in five years).
Cheers,
Geoff Glave
Vancouver