A Glock and most other striker fired guns, at rest, does not have the striker under full tension. In theory it cannot go off due to mechanical failure because there is not enough tension on the striker to ignite a primer. A XD, and some others, have the striker fully tensioned when at rest. In theory a mechanical failure that allows the striker to go forward could cause an accidental discharge.
Is it a meaningful distinction? Probably not. Is it a distinction that matters to selection committees? I'm sure Glock (and most other striker manufacturers) makes the difference abundantly clear when given the chance to a committee