So recall that the plans for the teams owning the second, third, and fourth picks (and so on) are all built on conditions because they don't know what you're going to do. Those teams are rivals to you, and also your trading partners.
If they don't know who you are looking at, then there is more time they spend looking at the guy you want to take, and less time they spend scouting others. Your smokescreen is a small way of helping them make a mistake down the road just because of time constraints.
Further, if you want to trade down, you want no part of your hand tipped. If the trading partner thinks you're interested in their guy, they'll offer more to get him. Plus, your trading partner also view the people behind your pick as rivals. The less your rivals know about your plans, the more likely they are to make a mistake or overcommit.
And finally, it's good press. This is the entertainment industry and people like drama.