It is a bit more complicated than that.
These are the main features that had been considered in the past when designing new base materials:

-) strenght
-) optical features
-) coatability
-) flamability
-) area/dimension stability
-) producibility/costs
-) archival stability


That plasticity issue might be subsumized under strenght, though should get aposition of ist own, but interestingly I have not found it discussed in literature, though on other occasions.