The MZ X500 excel in piano's, e-piano's, bass, organ and synth sounds. I really like these sounds especially the hex layer sounds but is this worth 1000 euro? I don't know yet but I am still interested in this casio.

I have been open by listening to some demos of the instrument, and if I happen to see it in a store I guess I will try it, too, but Maten expressed it in quite a general way, saying the developers focused on electronic sounds and EDM music, and orchestral sounds are not what the instrument is about.
I have always considered all brands to be potentially interesting, but I'm not a Casio fan to be eagerly interesting in an instrument when a main demonstrator expressly turns me away from it.

Where it comes to piano, the mz-x falls short of the real Casio DP..

I think the guitar sounds are atleast very decent
And the string sounds are actually quite good from this video..

And all the other sounds, and acompanying styles i havent heared demoed...

Let me float a possibility by you. Sales to young musicians (can I say the EDM crowd, although there are plenty of older people interested in that?) are very important. Many won't even look at arrangers because they associate them with "elevator musak." So Ralph says what he said to try to attract the EDM crowd to the machine. It doesn't necessarily means it isn't competent in other areas too. That remains to be seen. Frankly, to my ears many of the non-synth sounds I hear in the Ralph Maten video the OP posted are encouragingly good. And Casio has evidently implemented something very much like Yamaha's Megavoices as well as triggerable articulations. A little late to the party, granted, but they are there now. Hopefully future videos will highlight these aspects as well as the styles. Given the newness of the product I choose to remain positive about the potential of the MZ-X500. Casio knows they have to get it right.