I wouldn't say 'triumphant'.
I think for many there is an expectation that an an airline flight must include certain features, that is nothing more than a hangover from the glory days of air travel. Once upon a time getting in a shiny jetliner was an exciting and glamorous event. A restaurant style meal at 30000ft was an event, and the holiday began as soon you boarded the aeroplane.
Times have changed and air travel is far more mundane. The holiday doesn't begin when you board the plane any more than it begins when you get on the bus to get to the station to get on the train to get to the airport. In fact air travel is like a bus: just another form of public transport; sad but true. We have come to expect the traditional service even when it is superfluous (why do we need a meal service on a 2 hour, mid afternoon European shorthaul flight). The locos recognised this, made the extras optional and reduced the base price. The public embraced this.
Most of the complaints come from those who pay the loco ticket price but still expect the legacy service. The full service option is still there if you wish to pay for it so I don't have a great deal of sympathy for these sorts of complaints. If you get on a loco flight with the same attitude as when you get on a bus or a train you'll have few problems.
I may work for a well known budget airline but I am certainly no company spokesman and I see many negatives in the overall business model, but I do see the positives of using the system to enable cheap travel, if you apply a bit of common sense. I have nothing against the legacies and think there is a time and place for full service - my last passenger flight was in Virgin Upper - absolutely fantastic but impossible to justify for routine travel. You pays your money, you takes your choice.*
*or some similar old expression.
In other shock news, it may be cheaper to hire a limo with a free bar than get on a train and buy 40 bottles of champagne and a reserved seat.