Going off the usual price for apps ($2.99?), and a 'bunch' is probably about 25 apps, then replacing all your paid iOS apps with paid Fire apps would probably cost you $75.
So ignoring anything else, a lot of people would actually value their $75 sunk app costs greater than the $350 difference between that iPad and the Fire. It's a pretty interesting lesson in humanity.
And there is always this one little app whose substitute would be perfect if only it didn't miss this one little feature.
Every review of an Android tablet complains about how the software is buggy and the ecosystem isn't there yet. Still. Again, I was never convinced there was a larger market for tablets; just a market for iPads.
In my experience, it's very difficult to find the same apps in the Fire store.
You can just install android on the Kindle Fire and be happy, though.