I think Vintage players are justified in complaining about this announcement. I am not usually a Workshop player, and I think this was a horrible decision. It is not because "my favorite deck" isn't legal anymore, and it makes you sound dumb if that's your response when people complain about a restriction. Presumably, the people on this forum have been playing Vintage for long enough to remember that there are deeper problems with the way this format is managed.
Format management may not be as interesting to everyone as it is to me, but for people who have been talking to Wizards, reading interviews, and following articles about B/R for 20 years, it is well-known that the DCI doesn't take Eternal formats seriously, and none of the committee members are experienced with playing either of the formats (no matter what promotional youtube channels you may have come across). The decisions are made with no research, no tournament experience, and no consistency. The factors that influence WotC in these decisions are generally bad for the formats, and include embarrassing methods such as obsolete magic theory, irrelevant historical decisions, anecdotal format experience, image concerns, and the echo-chamber of the personal channels that have formed over the years. The process does not rest on anything intelligent, and you should not give it the benefit of the doubt.
The rational response to mismanagement is to complain, or even start your own unsanctioned leagues with better-managed restricted lists. This hobby is not supported by WotC in the first place; it is we the players that make it happen and have kept it alive. I believe the situation with Legacy is more complicated, but Vintage does not need the DCI at all. We find each other. We build our own communities (thanks to Steve and Andy). We fund, promote, run, and judge our own tournaments. We bring ourselves to the tournaments, and we even make our own cards. I also believe that a subset of our players knows better than WotC what is best for the format, and I know for sure that a few of us have better methods of making B/R decisions than they do. Their corporate obligation to the descendant products of Magic: the Gathering creates a centralization that has been more stable than a community authority, but that is the only reason we (and not all of us do!) let them define our format for us. In Vintage, the DCI is a relic that we pay attention to out of habit.