Other keyboards are seriously annoying by either not having prediction, putting them behind late T9s or they have predictions which seems to be made by someone who almost actively try to make me look stupid.
If I had a penny for every time a native speaker wrote "would of" instead of "would have" in forums, I'd be a billionaire. "Their" / "They're" / "There" is also common.
But the funny thing is, I noticed I would make similar errors after being immersed in a native environment after a few years time. Somehow I just say to myself what I wanted to write, and the slip-up happens. So native speakers are more prone to this, but it's not only there privilege!
LOL, you won't fool me.
My belief was that it's because English is not spelled the same way it sounds, so people who learn it are forced to memorize pronunciation and writing separately.
I'm guessing when you read people making this mistake over and over (I even saw it done in news articles) I guess your brain starts equating them together :(
I'm thankful for those people correcting it, although I think it is a losing battle.
This is more of a fun side note: It's more likely that they're a native speaker. People who learn English as a second language generally don't make the their/there mix up.