Forgive any typos. I'm doing this on my phone.
I'm basically a newborn in vintage. I've been around since sometime late November of 2015. Something like that, so I've only been around during the Gush era. Take that as you will, positively, negatively, or neutral. Obviously, we all have a right to share our opinion.
My concern with the banning, is not the banning itself. I think there was/are legitimate concerns about Gush and Probe (not to mention other cards). It could very well be the right move for a better format. However, I don't want to get into my exact feelings on whether I agree or disagree with the restrictions of the cards, but of bannings/restrictions itself.
The concern I have about is this restriction seems to be more about outcry of people than actual data. During the prior b/r announcement they explicitly said they wanted more data and feedback... and explicitity mentioned the European vintage championship. Unless I'm mistaken (please correct me if I'm wrong), there was no domination by Gush in that tournament. I'm not sure where they are getting that data.
Granted, I do understand that this is a multi layered on how you can view the meta and Gush's affect on it. I won't disagree with that. For example, you can make an argument for Shops dominance because of the the way blue decks are constructed. You're right, low land counts and free spells are awful against shops.
However, how can you possibly quantify exactly how much Shops dominance is because of Gush and how much is because Shops is just damn good (which it is)? Honestly please tell me if you can.
Shops will always be a strong deck against blue. Its purpose in itself is to take advantage of the things blue players crave - cheap spells. That's the nature of Shops. Outside of WOTC nuetering the deck completely, that's not going away.
I feel the same people (not all) who complained about the VSL having an affect on the meta are the same people cheering this on. That doesn't make sense to me. How can you rip into WOTC for listening to the VSL, but cheer WOTC on for this? If the VSL honestly influenced the DCI on multiple occasions for multiple restrictions, I argue that is not a good thing. Regardless if the restrictions are the right call. The VSL is entertainment, it's not supposed to be a snapshot of a true vintage meta game.
Another concern I have is a general concern about the Magic community that I've seen a lot of lately. There seems to be an overriding focus (and I'm not speaking just of vintage), the solution to any deck or archetype becoming number 1 is to ban/restrict a card. Banning/restrictions should only happen, in my opinion, as an absolute last resort.
Let's look at Modern as an example. They ban Eye of Ugin (a very legitimate format warping move). After a while, things start moving very fast. To curb some of the speed, people cried for a Become Immense/Probe/etc banning. Wizards then banned Gitaxian Probe. Now Death Shadow archetype is number 1 and people call for that banning.
Is that the solution magic players go to now? Instead of finding ways to attack the best deck, we call for a ban/restriction immediately? There will always be 1-2 (most of the time) best decks in the format. If you ban/restrict a key card, something else will move in to take its place.
The same thing is happening in Legacy. They ban sensei's divining top and people are now calling for a ban of Deathrite Shaman. Before any magic has been played, tested, and letting the dust settle, another ban outcry is happening. That to me, is a concern.
Mentor will keep on mentoring and will most likely still be the best blue deck. Shops will still be excellent. I don't know exactly what Mentor will look like, but it will be a mainstay. However, people are already talking about the next restrictions in vintage. Can't we take a step back for a moment, play some games, before getting into that discussion? Or are we going down a path of constant restrictions in vintage? Will we see Mentor, Mental Misstep, Thorn, Preordain, Workshop, Bazaar, Ancient Tomb, etc. get restricted in the future? I sure as hell hope not. The format needs powerful, unrestricted cards to be fun (for me). Obviously that statement is very subjective.
In a lot of ways, this is the biggest concern to me is how people are treating bans/restrictions. Almost as if it's a tool to combat decks they don't enjoy. Which, sadly, starts to mask the true needs of ban/restrictions. B/r's, as I said, should only be used as a last resort. Now, with all the outcry, this picture is becoming muddier and muddier.