There is a substantive difference here insofar as you can actually have an event datetime with no end at all (which you can’t in Google).
This was requested, and I think it makes some sense for certain types of events. It also allows the events plugin to potentially handle other types of ‘times’ (i.e. other than actual events, which have a duration, even if the duration is indeterminate).
I understand why Google has taken this approach, but technically (i.e. grammatically) this doesn’t make sense:
There is no time gap, so it’s not really “8am to 8am”. It’s just an event at 8am.
Also (while I’m being really picky ) the entry on the calendar UI is incorrect insofar as it suggests the event takes 1/3 of an hour, when I’ve recorded it just as “8am”:
Of course Google calendar is generally pretty great, so I’m not about to die fighting on this hill, but I do think having the ability to not have an end at all is worthwhile.