I agree. They don't do too bad, but the best is still what I would call "broken English". Enough so you can figure it out, but it doesn't read smoothly.
For example, I have this line in one of my plugins:
"The following options were not paired correctly. Be certain to check their information carefully before you remove them."
The (human) Dutch translator gave me this for it
"De volgende opties werden niet correct gekoppeld. Wees er zeker van de informatie zorgvuldig te controleren voordat u deze verwijderd."
And Google translate gives me this English for that Dutch
"The following options were not properly linked. Be sure to check the information carefully before you removed."
True, I don't know Dutch so maybe the translator did wrong, but I'm betting the Dutch more approximates the original English than it does the Google English.
And I have no idea how good this Google Dutch is for the original English
"De volgende mogelijkheden werden niet goed gekoppeld. Wees er zeker van om hun informatie te controleren en zorgvuldig door voordat u ze verwijdert."
But it gives me this Google English for the Google Dutch
"The following options were not properly linked. Be sure to check their information and carefully before you remove them."
Which is NOT what it started with. So something definately got a bit mangled somewhere.