It's not about whinging so much as an expression of a degree of disappointment. If you've ever completed a survey about a hotel stay or holiday, the question isn't a bland "did you enjoy it". It's "did it meet your expectations", or "did we exceed your expectations"
Not just based on rumour or slot applications, the reasonable expectations here were that CX would go daily and those expectations were not met. Hence a degree of disappointment. The fact that LGW has got a daily flight didn't help.
But yes, the fact that we are getting an extra flight with more premium seats and a slight increase overall in pax capacity on a newer a/c is welcome.