which will probably have core engine inferior to Taleworld's M&B2
Where did you get that impression? If anything the engine
will be much better than Taleworlds. Don't forget that without cmp's goodies MNB1 would be a much more horrible game, in every aspect. Clearly the talent is on this end not the other way around.
which they will most likely buy as well.
I won't buy Mount & Blade 2 at release. I don't see a reason why I should. Perhaps the Single Player mode would be worth buying it for but nothing I personally am concerned about. If there's a steam sale at some point then sure though, just to see the difference.
So how come you say that Day-Z on older engine will matter that much?
As explained already countless times with great examples.
Here's another:
ArmA 3 = Mount and Blade 2
DayZ SA = Mount and Blade Warband + WSE1/2
For this example to work obviously we have to PRETEND we had tried the engine for MNB2, and that it would be an amazing engine, which fixed and enhanced every aspect about MNB1, took it worlds further.
Now with that in mind, why would I play a lesser game when there's equally good games available in the new engine which have the exact same gameplay (Dynamic Zombie Sandbox mod).
Don't forget that the modded versions of DayZ, at the private hives, are miles ahead normal DayZ as well.
It isn't like I won't be buying DayZ SA though, everyone who played the mod should, a small sum for the many hours of fun already had.
Either way no point in discussing it for too long :P we'll see how it works out when DayZ enters open beta.