Unfortunately you have seen it as a negative instead of a positive as it allows buyers to see  there is interest in the item and there are a number of people watching. As a buyer you do not really know if many people are interested in an item so you may just stick it in your watch list not knowing you are  not the only one and at anytime others may pull the trigger and purchase and for one off items you end up missing out.

Of course not every item has watchers and get constant sales but I find this is more for needs instead of wants.

I have had many listings with a number of watchers but only 2-3 left in stock and you will find after one sells the rest will go over the next few days followed by a message if you have any left. Showing the number of watchers would have created a sense of urgency just like a crowd at myers going through the clearance rack.

This is my take on the feature but I may be wrong.