No more so than the reasons to go with banana plugs over bare wire.
Banana plugs don't offer any significant performance improvement over traditional bare wire through binding posts. They are a convenience more than anything, and a fun side project at least.
When I wired my basement theater, I installed binding post wall plates at each speaker location as well as in the wall behind my receiver. I made custom patch cables and used banana plugs where possible. It wasn't cheap, but it looks good and made it easier to swap receivers last year.
Spend what you feel you can spare, but understand you won't "hear" any difference.
In reality, not really. Contact between two dissimilar metals in the present of a current can cause a type of corrosion known as galvanic corrosion. This may be important if someone lived in a humid, coastal area where corrosion could be a problem. Gold plating adds a protective layer that does not corrode. This is why you'll see gold plating on hdmi connectors, banana plugs, etc.
I use banana plugs for all my speaker connections. The gold plated ones for 12awg wire was not much more than non-gold plugs, so that is what I went with.
As Jason already stated, you will not hear any difference from bare wire. The plugs are a huge convenience for me, though, especially on the receiver end of the connection. It is much easier using plugs than attempting to thread bare speaker wire into tightly spaced binding posts on the back of most receivers.
They really do make it so much easier and look better. Crutchfield sent me some Gold plated ones with something I bought so I set them up and now I need 10 more. I can get 10 gold tips for about 10$ but 1 pair of plates are about 8$ by themselves. That's why I questioned the difference
Plus one to all of the other comments posted. Using the connectors makes it easier to work with. You can quickly remove or insert connections depending on your set-up. As far as sound, there will be no difference.