It's impossible to not get a legendary after opening 40 pack without any. You probably got your's in the first 10 pack since you have to open a legendary in the first 10 pack at the beggining of an expansion. So, if you oppened your first legendary after 10 packs (the maximum possible) 42-10= 8. you should get a legendary in the next 8 pack (worst possible scenario).
This time i opened 150 and got 5 legendaries... Pretty bad result... but then in Kobolds I got 7 from 100... you win some... you lose some... it sucks but opening packs is all about RNG. Next time you could be the one opening 1 every 10 packs!
You're a fuckin asshole bud. 42 packs is a lot of money if you paid for them, and getting 1 legendary kind of ruins your whole experience for the expansion. The rewards system is clearly broken here, and maybe you could be a little more sympathetic to someone trying to have fun playing the exact same game you are. People like you make me sick.
I keep track of my legendary pack openings and it took me 39 packs to get ixil whatever from Kobolds. And then I'll open back to back gold legendaries in classics. It's all RNG just like everything else.