There has been a long running thread on Apple forum on this. Among others that are scattered there.
Touch ID Being Erratic
That long 73 page thread started in 7.0.
Since 7.1.1 released, only 10 or so people (fewer than 2 pages) posted in that thread.
None of my friend has any issue with TID anymore.
I don't think it's fair to say "a lot" of people still have issues with it. If you read the post, these folks' TID fail quickly. It may be edge cases for Apple to work on. Majority of the folks should be okay.