HELLBOY 3 was not going to happen. 100% dead-in-the-water. I adore the GdT films and would've LOVED to see his trilogy completed.
BUT
This reboot is going to happen. In a time where GUARDIANS OF THE GALAXY makes nearly half a billion dollars world-wide on the weekend the film opens in the USA, Hellboy and other weirder properties WILL be revisited by studios. There is just too much money on the table.
Neil Marshall is awesome; he's no GdT but he's awesome in his own right and he could have an awesome take on Hellboy.
Dunno so much about the actor playing Hellboy.
Getting upset about an announced movie is kind of sill without knowing literally anything other than director/star. Wait at least until we know the tone of the film, know a storyline, see trailers, etc before making a yea/nay decision. The Hellboy universe is so ripe with interesting stories it would be a shame to ignore the property just because a specific director is no longer attached.