Oldairhead 

Well, that is partly correct. Probably the more significant initial reason was to make an effort to try and preserve the "white roads" of Tuscany and surrounding regions which were under threat of being paved and further developed. The vehicle they used to accomplish this (no pun intended) was the bicycle, and theme, specifically from an earlier era when these roads were used by professional racers. Creating a movement of sorts through a sporting event to accomplish that end. The vintage aspect of this new event was in keeping with the history of the area as well as to honor the historic use by the racers who are so highly regarded in Italy. It all tied together very well and made for a very attractive package.

Now, as we all know L'Eroica in Italy and some of the other franchise venues have specific days or routes for modern bikes to participate in the event. It is not exclusive to vintage cycles anymore and has not been for several years. And, when Bianchi (a sponsor almost from the beginning) decided to support the event in a bigger way it was in part to promote their own products. It is no surprise that they would not only create a bike specific to the event but also try and capitalize on the brand and image. It is simply how things are done.

From the L'Eroica website:

THE HEROIC SPIRIT
The beauty of fatigue and the thrill of conquest Eroica is more than a cycling event; it is a lifestyle. It’s what leads us to face our difficulties with tenacity and patience and appreciate times of struggle as a challenge gratefully accepted. Riding vintage bikes on gravel roads recalls the heroic cycling of Coppi and Bartali and recovers the core values of a great sport still able to fulfil the needs of today through the experience of fatigue in all its raw grandeur. More than just a challenge, Eroica also seeks to reawaken a taste for adventure, the unexpected and the journey. A way to relaunch cycling, create respect between riders and inspire new models for sports and life.

I have ridden a number of Eroica events at several of the different venues, as well as supported the event on my motorcycle twice. Once on a vintage moto and then again in 2019 I supported the modern version as a course marshall on a new BMW GS bike. I think that the above statement from the event leaves enough wiggle room to be welcoming to a broad range of perspectives. Also, keep in mind that through coming years the event will likely continue to transform as it's corporate owners see fit.