The problem is there is no barrier to overcome to get listed on an exchange,just a few tweets,a few words in IRC etc and you're on.
Devs should need to prove themselves,and be willing to go the extra mile to do so if they want to be listed on a good exchange,there should be some minimum standards in place to filter the crap,it's not a complete solution but it's a start.
yes there is bribery
Something the major exchanges could do, but expect they won't, is use some sort of minimal standards before listing any ipo/ico/icd coins,
even if they didn't run the ipo through an exchange.
It could be something basic, like that pod or coinssource trust rating + code review. If there are lurking premines, the coins won't be listed until the premines are destroyed.
Note that I don't say to do this for every single coin listed, as that would be a lot of manpower, and financially it may not make sense ... as if bittrex doesn't list a new coin, someone else will. But even though there seems to be a lot of ipo coins out there lately, there aren't so many that this isn't feasible. IPO coins naturally hold a higher risk than the standard coin, due to the devs receiving funds upfront. So it's not unreasonable if exchanges hold them to a higher standard.