not all of the ICO could deserve to be bought back when after ICO is completed. of the many existing ICO only a handful could produce. and on the selection of this analysis, the ICO will determine whether good or bad results of elections to the ICO that will be purchased. even this could be a strategy exactly where to get coins from the ICO is priced pretty cheap.
Being an investor, I would say they deserve to have a buy back program, after all it's the team's decision because they control the total amount of money raised during the ICO. With a buy back program, investors will happily accept it because it will help the price to stay at ICO price or increase the value, either way, it brings positive result to the investors.
However, there should be some kind of limitation because amounts collected should be allocated more on the development side.