I feel get is acceptable style if you actually want to fail when there is no data to be had.
If you don't have a default value to provide, nor an alternate code path other than "sod this, I'm bailing", get is ok. Not quite as good as using a more specific exception through orElseGet, but not bad, exactly.
Also, if you have just called isPresent (and assume your data to be immutable), then get is ok - the alternative being to manually throw something like new IllegalStateException("the impossible has happened!"), which is not that much more useful, and is a pain to have to write all the time when you know it will not get called.
>Using get() is just bad style and so is returning null where you could return Collections.emptyList().
I agree that you should never return null, but if get() is bad style I think you should send out that memo because I haven't yet seen codebases that agreed.
If you don't have a default value to provide, nor an alternate code path other than "sod this, I'm bailing", get is ok. Not quite as good as using a more specific exception through orElseGet, but not bad, exactly.
Also, if you have just called isPresent (and assume your data to be immutable), then get is ok - the alternative being to manually throw something like new IllegalStateException("the impossible has happened!"), which is not that much more useful, and is a pain to have to write all the time when you know it will not get called.