I think Review Bombing is a bit in the Grey Area. On one hand, Review Bombing can send a clear message to a developer to stop something that they are doing that they have done recently. On the other hand though, reviews are supposed to help other people decide on rather or not they should buy a game. It very depends on what the reason for it is and how someone review bombs the game.
I think what matters is 5 things. One, what is the cause of it. Two, how bad is this problem and how negatively is it going to affect consumers. Three, are the developers listening or just ignoring feedback? Four, are the people who are going to leave the negative reviews going to change them to better reflect the game? Five, was it really necessary to leave a negative review?
I think one example of Review Bombing that I'm okay with is with PlayerUnknown's Battlegrounds. It has experienced 3 very nasty controversies that had pretty much hurt PlayerUnknown's, Bluehole inc, and the game itself. Continuous waves of banning/suspension to players who were allegedly Stream Sniping and Stream Honking without giving any sort of proof that these players were indeed Stream Sniping and Stream Honking since both of them are very hard to prove and even Blizzard have pretty much said that its really the Streamer's responsibility for it since their actively and willing giving away what they are doing and there even ways that you can counter Stream Sniping and Stream Honking from happening. Microtransactions being added after PlayerUnknown (Brendan Green) stated that microtransactions wouldn't be considered until after the game was out of early access. Lastly and most recently being Bluehole inc saying that Epic Games should licenses them for adding a Battle Royale game mode into their game Fortnite and mentioning PUBG in their video announcement about it as an inspiration. Personally, just the banning of players for allegedly cheating by using a method that is very hard, almost near impossible, to prove. The only thing they did say was they had "data" and some players were continuously trying to join a streamer's lobby, even though PUBG is in Early Access and is expected to have many problems such as the Matchmaking system putting players against the same ones over and over, and yet they are not even taking that into account. Bluehole and PlayerUnknown have not done anything given player response to the way they have been dealing with it, especially with players who have stated that they weren't even on Twitch when it happened or don't even use Twitch at all, and I personally don't want to buy a game which while it may be fun, I have a chance of being banned because I killed a Streamer in game and was accused of something that I didn't even do then be banned or suspended and be unable to play the game for just a limited amount of time or ever again. At least with something with GTAV, if I get banned from the Online portion, I can still enjoy the game in the singleplayer portion.
Fallout 4 is another game that is getting review bombed at this moment due to Bethesda's Creation Club being added into it where you can pay money to add certain mods into your game. While I can understand why a lot of people are upset about this, and I can understand the possibilities of some mods being way too overpriced and more developers trying to pull something like this off again, I don't really think the Review Bombing is really necessary because I can just ignore it, not use it, and play the game just fine without it hindering my enjoyment. I mean it will hinder my enjoyment a bit seeing how the mods in the creation club are installed regardless if purchased or not, but it's not the worst thing that can happen. Plus a lot of people, big and small, have already panned this idea before.
One last example, and while it is a small one and is nowhere near as a big as the other two, I do want to bring up as an example of one where I think the Review Bombing was just stupid. That incident being with DotA 2 where it's getting review bombed because Valve has not released Half-Life 3 or Half-Life 2 Episode 3. That is something completely irrelevant to the game and doesn't really inform me about anything that will hinder my enjoyment of the game.
When it negatively affects a large amount of consumers, I think that is where I think Review Bombing is pretty much okay to happen. When it's something not with the game, and more like something didn't happen that they wanted or its something that isn't a big deal and isn't negatively impacting the consumers. Review Bombing does have its own kind of power, and when given it can change a way a game is handled, but I think a lot of times, it is just unnecessary. If it is due to that there is something going with the game that the developers did and will hurt my experience with the game, Early Access or not, as long as it in a state that I can buy it and play it, like with PlayerUnknown's Battlegrounds, then I'm okay with it because I want to be informed about it and know that I shouldn't waste time and money. However something with like the Creation Club for Fallout 4 or people wanting Half-Life 3 and taking it out on DotA 2, or even the case that happened with Firewatch, that is where I don't think it is needed and in the case of DotA 2 and Firewatch, is anti-consumer because what happened with those is not affecting the game or someone's enjoyment and is leaving impressions to other players and changing their mind from purchasing and playing a game that they could enjoy.