FEA - meshing - when too many elements fail to calculate - any solutions coming for this issue?

Hi - I tried to use 3D tetra meshing, thinking this will resolve same issues as NX nastran on NX9. 

The mesher is completely different (WHY?) and so does the ability to solve high number of elements (even if meshing succeeds, it will not give a solution due to lack of memory).

I tried to ask support why they don't combine the same mesher and solver as NX - and got no good explanation. I undersand both are siemens and both are NX, but apart from this - why they don't work on the same engine like they use parasolid?