Hardly surprising. Working the coach cabin, you have the opportunity to do one run through the cabin with beverages and pretzels, and then retire to the galley to play on your phone. One more pass through to collect the trash a bit later. Then that's it until it's time to land. I think it's misguided to categorically label First/Business Class fliers as "demanding" - a premium level of service is what has been sold, after all.
For example, Delta First Class is advertised as follows:
For amenities and superior service you won’t find just anywhere, choose First Class on your next Delta flight. You’ll enjoy personalized service from a dedicated flight attendant, Sky PriorityŽ service throughout your journey and a thoughtful travel experience from start to finish.
Yes, I'm sure there are passengers who occasionally take it over the top. But flight attendants who hide behind "we're primarily here to ensure your safety" as an excuse to provide minimal service don't belong working a premium cabin.