People view incidences like this based on are they Mercedes/Ferrari fans OR Hamilton/Vettel fans. It's hard to be objective.
FIA have declared Lewis was consistent restart to restart. He should've been punished IF the first restart contravened the rules. It didn't nor was there a complaint from Ferrari. Complaints to the stewards are made via e-mail, and let's just say, many teams aren't shy about letting Mr. Whiting know their views.
My speculation is Vettel was looking for a chance to make a pass on Lewis during the restart. The crazy long first straight of Baku after the restart was probably the only place he could on the track. The minute he makes contact, he goes on the radio and says "Lewis brake checked me."
I understand why Vettel may have thought it. He was trying to anticipate something. It' also easy to get distracted in the car setting the adjustments for a rocket run to the first corner. Mistakes happen, and they are forgivable. Radio gamesmanship is now a common thing in F1. Memories of Alonso and Vettel whinging about each other in Abu Dhabi? a couple of years ago is a great example.
Pulling alongside a competitor and raising your hand is ok in my book. (I still remember the Coulthard/Shumacher exchange which was more than a raised hand.)
Deliberately crashing into another driver is wholly inexcusable. If I were FIA (and I'm not) I would disqualify Vettel from the race and give him a two race ban. Ferrari would appeal, and I'd reduce it to one. (I love in the old days of F1 if you appealed a decision looking for a lesser punishment, you may receive additional punishment for appealing!) I doubt this will happen. Schumacher was once given a one-race ban for simulating a start and jumping ahead of Damon Hill prior to the green flag of a grand prix.
Perhaps you think I'm overly Draconian in my view. If there were video of Perez/Grosjean/Palmer deliberately crashing into another car, people would be screaming for long bans.