"This one hasn't sold yet? Lets update..."

I haven't actually seen this one, having become absolutely sick of ebay and its exploitative ways, but let me guess.

"Lets update" leads to "helpful" suggestions.  First on the list will be.

"Sponsor Your Listing"

Next, for those already Sponsoring.

"Try one our other Promotion Strategies"  (Which cost just a little more)

As you say and I agree with you,  "most of us know what we're doing and just want to left alone to get on with it".

So, if ebay wants to increase revenue, it should DO what we pay it for (one way or another). 

Get back in the background and become merely  a platform to bring sellers and buyers together.

Give the buying public free and un-restricted access to all the ads. sellers are paying you (one way or another) , to host.

That led to your success.  It might even save you now.