A brother on another forum posted this on the topic:
Maybe the reason the speakers still speak even though they see whatever is going on is because by speaking, at least they hope that they might be able to get through to these jaahil people in some way. Yes there are alot of jaahil people still out there. Especially at events like these. Its ok to denounce some of the things that they are doing ... but at the same time there need to be people who will teach them what is right and the right way to worship Allaah.
If they didnt say anything and just walked away it would be alot worse because the people would still be jaahil.
I'm not supporting this event by the way and I don't support these nasheed artists nor some of the people they consider as "Shuyookh" or "People of knowledge"....But I remember last year that some people with knowledge like Shaykh Suhaib and Yusuf Estes spoke at the event. I don't think they liked being there but nevertheless they accepted the invitation, maybe because they probably felt that by speaking at an event like that they would be able to remind the people with whatever they were able.
The way young daee's look at da'wah is alot different to the way older and daee's look at it. People don't accept advise when you want them to. It takes time to sink in.
Unfortunately its not a perfect world. There is still alot of work to be done. It has to be seen as a gradual improvement not an overnight one. People resist sudden change. Especialy when they've been used to it for so long.