Seller's don't have any control over new eBayers with zero or very low feedback bidding on their items. It's not like you can block them all from initially bidding on your stuff. I sell high-end things every week and often get bidders with zero feedback who bid on my items and I've never shill bid in all of my 9 years of selling. I just ask them to email me for permission prior to bidding and more times than not, they do. I rarely have a problem with any newbies.
I have my preferences set to automatically block (1) those with no PayPal account and (2) those who have 2 or more unpaid item strikes in the past 30 days. That's about as far as you can go with blocking people from bidding on your items.
Just because you see someone new bidding on an auction you want to win does not mean that the seller is shill bidding. Sure, it happens. But that's not always the case. LOTS of new people join eBay every day and everyone starts off with zero feedback. A seller would have to pretty much sit at their computer 27/7 to block these bidders when they pop up if they did not want it to "appear" as if they were shill bidding.
As a buyer, I don't worry about things like this. I know how much money I want to spend on an item and that's the price I bid. Period. If it goes higher, then so be it. At that point, it really doesn't matter if shill bidding (as wrong as it is) was taking place or not. The item has gone beyond the price I wanted to pay anyway.