Mmm this is like asking whether you can disable Hildon on an individual device. Why would you do that?

PS: alright, not a good example since Hildon is providing the Desktop as well. Let's say that it's like willing to "unable" Python (in an hypothetical case where Python would be available and pre-installed).

Btw, if in the future there are pre-installed widgets/apps developed with Web Runtime, "disabling" it you loose those apps. Why a user would like to do that?