To address Awha, Physic, MsQI.
The info came from an interview with the Director Yoshi-P. Also, the fact that people complain about BLU posts, and they're something discussed in other forums/sites then that kind of paints the picture of many people (of those who care) that do have a problem.

The thing with BLU is that it's an old job. It's a job that over time garnered a sizeable fanbase, which is why people are protesting to begin with regarding its implementation, and I know I'm being repetitive, but the Japanese aren't happy with it either. While I realise that some people do like it, there is a different set of things that come with it. The people who would have accepted content, are likely to be people who would have accepted any content, like Eureka or the "limited job" system as a "thing", not because it was a good idea or they really like them, but because they wouldn't have cared either way.

Now, this apparently didn't fly over everyone's head as SE wished that it did. But as Zsplash implied, the way BLU was implemented wasn't for the sake of implementing a class into the game, but it was just as filler as a means for making cheap content. I do not think this is what any person who likes BLU would want to see their favourite job to be used for. Hence, coming back to the Gunbreaker, I do not think that any class should be used for a "limited job" experience either but it is weird they decided with causing dissent on purpose when they could have used something that would have caused none.
The situation is eerily similar to what Blizzard did with the Allied Races. They were used at a time of drought and were used to market BFA, with one major difference, that these races were not restricted in what they could do and could be used just like any other, and they were complete. The only thing one needed to do was work to unlock them. It's a different level of commitment and effort compared to what happened to BLU.

The fact that BLU will never be able to do anything else will always persist as a limited job, so it will never be an experience that will last more than 1 week because these limitations inherently make it so. Even though there were other means to make content and to create such content and do it for every class as I said, by doing something like the Carnival for everyone and giving actual rewards.

Overall, this ordeal sets a dangerous precedent. Who knows how many other jobs are going to be butchered for the sake of easy content? Had the "limited job" been used to, yes to gouge interest for the new expansion, BUT only showing an unfinished class and using the "limited job" system to test it live and subsequently finish it for use like any other class at a later date, maybe in the middle of Shadowbringers or a couple months after the release, then it would have been ok.