IMO hazard maps are perfectly fine and I like them. Some of them offers real hazards but most of them limit the playability of certain play style forcing the players to adapt.
Hazard Dagger: very atmospheric. My very first hazard game was hazad Dagger/gold/collectors and it was amazing and frigthening at the same time. It was immersive and challenging to fight an „invisible” all powerful enemy. I think it is a legit hazard, you cannot see too much in a sandstorm and it limits the playability of the popular tower camping/sniping playstyle.
Hazard White: there is simple solution: stay inside the building. I think that it is a legit hazard too. It limits the playability of the CQC styles and sniping outside but I see no problems with it. If there is a giant snowstorm outside then sure you want to stay inside the building. If you really, really, want to go outside then swith off HM, or wait for rage to wear off.
Hazard Glacier: one of my favourite hazard maps that offers a real hazard: George the seeker swarm. George seriously limits backroom camping and camping in general. The beautiful thing in George is that not just he is a true hazard but he is unpredictable: sometimes he is total jerk trolling the players while in some other games he is almost invisible, forcing the players to adapt in each game.
Hazard Ghost: an other beautiful real hazard. It limits camping in the open. While it is dangerous it is completely predictable and you can plan ahead/around the acid rain as almost all the map can be approached by moving inside the buildings.
Hazard Reactor: another good idea perhaps with somewhat lacking implementation. I like the idea as it can be used strategically: most of the waves go through the reactor. The problem is that a lot of enemy units just ignore it and go through closed doors without taking too much damage, which contradicts the whole idea. The plus side that it offers a unique opportunity of trolling team mates.
Hazard Giant: the less hazardous hazard. It somewhat limits sniping but it is more favourable for grenade kits. Perhaps screenshakes should have been larger (though I know that it would draw many complaints) or grenades should be more scarce instead of being abundant.