While I am certainly not suggesting that the disappearance of the white race (to the extent that such a thing exists) or any race would be a good thing, I don't see how it would be a bad thing for race to cease t o matter to the point that the concept disappeared from both our consciousness and our genetic make up.
I do, and I'm mixed (half and half). I would like for my children to be able to recognize the Visigoths, the Reconquistadors, the Conquistadors, the Carlists, and the Cristeros as part of their heritage, so that they will receive the inspiration of their ancestors (the kind only ancestors can give) to follow in their footsteps in Golgotha. Being partially Mexican Indian, tradition in general is important, but when you introduce the influence of different cultures it becomes difficult to honor because the traditions of both, more often than not, conflict. For example, it would be somewhat difficult to try and have my kids take after my Spanish ancestors when I've married into a Mongolian family. Mongols who are culturally aware are very proud of their heritage, and as cool as I think it is, I have a problem with my kids having a "connection" with Genghis Khan and Tamerlane the same way I "connect" with the Colonial Spaniards.
Also, when looking on the relics of the past such as the Missions of San Antonio, while others look on them with admiration and wonder, I look on them with pride. It's one thing to admire the beauty of your brother's house, but it is nothing like your own inheritance as it is God's "portion" for you.