It's an absurd comparison. The culture with a clan who adopted Aveline and took in Feynriel (who, as developers have said, is technically human), with people who want to include the city elves in a free kingdom, and who signed a treaty to aid humanity during the Blight after losing two homelands to humans twice. You're vilifying the entirety of the Dalish despite the facts. When you say things like that, you should expect people to doubt your sincerity.
Since none of those disprove or dispute the comparison in question... sincerity doesn't really enter into it. Facts would, but you offer no facts or argument that are incompatible with the comparison. Sincerity would, however, apply towards someone whose invitation for a rebutal between a comparison of the Dales and a contemporary group is... to claim it is absurd, change the subject, and talk about neither the Dales or the comparison.
The Dalish Clans are not the Dales. This is a fact. The exceptional success of a legend hundreds of years past does not constitute a trend in any time: the facts of the attitudes and practices in the present that we see do. Some(!) wanting to assimilate and redeem city elves into 'true' elves does not challenge allegations of xenophobia. Collective defense does not mitigate motivations of self-interest and personal survival, especially in light of one of the issues of the Dales was a significant perception of a lack of support during a Blight. That's a fact, quite relevant to the subject of the Dales. These would be relevant facts, if only because they address your raised points (and not because they address the comparison).
To round it off, the claim that I am villifying the entirety of the Dalish is baseless. I condemn parts of their culture that I see as ruinous and self-destructive. I am dismissive of the accuracy and authenticity of a religion that, by its own admission, is as much guesswork as historical reclamation. These are not the entirety of the Dalish. I have contempt for ideologies of a reclaiming utopian pasts, and this is not a contempt reserved for the Dalish who cling to it. I am extremely skeptical of grievances of freedom and racial equality and religious tolerance that the Dalish (and, before them, the Dales) have never shown much a propensity as a collective when they were or did have power.
But the Dalish, as individuals, are not villainous for following a culture I disapprove of. I do not, and never have, denied that the Dalish can be virtuous and noble people: I simply believe they must rise above their cultural baggage to do so. I do not view the Dalish culture as malevolent: I merely believe it to be short-sighted. I do not support or condone or advocate Dalish massacres as some proper application of collective punishment for some sense of wickedness.
So when you talk about sincerity in an argument, and proceed to ignore the offered discussion and discuss things that are not only irrelevant but also inaccurate, it comes off as more than a tad... well, I'll let someone else decide what you come off as. I'm sure some people find you quite persuasive and reasonable, assuming they already agree with you.
But for me, someone who claims a comparison is absurd and never even addresses what parts of it they think are absurd, or provides relevant arguments about their position... that person is probably ignorant about one end of the comparison or the other. Given your reluctant nature to address inconvenient facts and trends of the Dalish, I'm honestly not sure which.