The author of the site, Steve Dryden, has been writing about the wine scene in the Guadaupe Valley for several years. He runs wine tours and, although I do not know him, I have run into him on several occasions when he has been shuttling tourists to wineries. He certainly is a booster of the region.
I did speak to him once while his clients tasted wine. Maybe it was a bad day as he complained that Mexican wines were too expensive for the quality and many of the winemakers didn’t know what they were doing. I hoped the people paying him to drive to the wineries that day were given a more upbeat assessment and enjoyed themselves.
As for the link to the article you attached, I agree with his assessment of the growth in the Valley, certainly over the past eight years I have been visiting. I think he is totally correct in claiming the quality, in general, is moving up. I too am a big fan of Roganto’s wines (although they are muy caro) as well as several others. I have had some very tasty and inexpensive wines from students at the wine school, La Escuelta in El Porvenir, and I think there are going to be more good wines coming as the students continue to learn the art of wine making.
Today there still are some rather poor wines but overall the wines are a far cry from the awful wines I tasted many years ago when visiting Baja Caliif. while I attended university in San Diego.
Casa Madero is based in San Lorenzo, near Parras, Coahuila, in the northeastern part of Mexico. It's one of the oldest vineyards in Mexico. Casa Madero's wines, especially the Cabernet Sauvignon and the Shiraz, are excellent. Here's a link to the website: