Travel first class on a plane and see if they pass by without offering or explaining what they've got, or don't come back to ask if you want anything else later.
Even in economy on a plane, they'll usually ask what you want by explaining what there is (a limited choice, yes, but not simply a trolley that you must try and scan from an awkward angle).
EC may have the best intentions on providing a first class service, but due to differences between a plane and train, and some staff that would rather not offer the service, you have what you get.
Why should someone who may be travelling first class for the first time on EC (the people EC want to attract and retain) have to know all the tricks, as well as knowing that if you don't ask in one go (however greedy that sounds) you won't get?
On a plane, I'd be embarrassed to ask for everything at once, expecting to be told 'we'll be back for that later, sir' and everyone around sniggering to themselves. On EC, it seems that you have to be as bold and brazen as possible to get anything, and be willing to demand more than you're offered - even though it's likely to annoy the staff who didn't want to offer a service in the first place.
There have been many good stories on this huge thread, but as long as there's doubt I know for a fact that I will never pay the extra for FC unless there's a deal that's too good to refuse. There's too much uncertainty and I always seem to be the one that is unlucky!
I suppose from EC's point of view, there will be a number of passengers who will travel first class regardless of service. If the service for them is bad, they'll not stop travelling - they'll just stop bothering to ask for anything. EC will then save money and be able to say that they offered the complimentary stuff but people turned it down (for the many reasons mentioned; i.e. you can't risk not eating then find there's no food!).