But why people need a sequencer in their keyboard ???
The concept of having it all in one place is the concept of ... having it all in one place. Sure you can sequence on a c-o-m-p-u-t-e-r. You can also sample and build sounds on a c-o-m-p-u-t-e-r. So there is no point in having those in a keyboard, right?
You sound as if trying to make fools of us all just because you know you can do your tracking on a c-o-m-p-u-t-e-r and we don't. Most of us have a c-o-m-p-u-t-e-r, but for each one's reason we want/ need a sequencer on our keyboards: because you don't want to carry another piece of gear, because you want to immediately catch an idea and don't want to waste time loading your DAW, because it's more practical since you don't have to deal with different buttons, faders etc, because it's more stable, because you enjoy the real-time control of phrase-based songs, etc. These are just a few examples.
If this serves to keep you laughing I'm ok with it but please don't laugh out of other peoples needs.