I don't think anyone abused the system, and I really don't want anyone to quit.
I can understand that feelings run high when an anticipated blockbuster trade is voted down, and things are posted in the heat of that moment.
Right now it takes four managers to overturn a trade. I think upon more reflection, that some who voted down this one might not vote the same way again.
Therefore I will leave the rule as 'league votes' on trades. I am new this season as commissioner, and as this past week shows, sometimes during the work week I may not spend enough time monitoring the league, so I don't want to take over sole review of all trades at this time. I will do so in the future if it appears that the league is simply voting down every trade.
As to the 'right' standard for using a veto, the arguments have been nicely put forth here, and on the Redszone thread in the fantasy section titled "The Fantasy Trade Veto". There are good arguments on both sides, but in this league, given the quality of managers, I think vetos should be very lightly used.