(Spoilers Extended) Daenerys not going to Asshai, why?

I always thought Asshai would've been where Daenerys path leads to. Only this year i saw that Martin either dropped this plotline or scrapped it later on. But as i looked back into AGOT, i thought this quote actually summed it up good:

She told herself that there were powers stronger than hatred, and spells older and truer than any the maegi had learned in Asshai. -AGOT, Daenerys IX

Martin describes Daenerys magic as this:

The whole point of the scene in A Game of Thrones where Daenerys hatches the dragons is that she makes the magic up as she goes along; she is someone who really might do anything. I wanted magic to be something barely under control and half instinctive.

https://web.archive.org/web/20151106235205/http://www.amazon.co.uk/exec/obidos/tg/feature/-/49161/026-1281322-7450821

It makes sense that Martin doesn't want Daenerys to be teached by anyone, because he wants it to be like described above.

At the same time though, Quaithe seems to tell Dany that she needs to go to Asshai, that the truth awaits her, while Daenerys herself thought before, that Asshai wouldn't have the truth. So what does that say? Does that make Quaithe the one with the bad intentions or will they meet somewhere else again and then she learns from her? Not forgetting Marwyn who is on his way to her and knows stuff as well. So what do you think?