I use a hatch based design for melee style bases but eventually I have to fall back to traps and guns (even on the first bm night) when the zombies overwhelm me - playing on 2nd highest difficulty and max zombies.
The thing I love about this game is there are so many options on how you approach the bm horde. Since you have to spend resources and constantly repair, eventually resort to bullets, explosives to fight off the bm horde implies that using hatches for a melee base is not an exploit. This is not a case where we build a base and just sit there all night doing nothing during the horde night, we have to get in there and actually fight the bm zombies (i.e. the whole point of being a melee themed base).
Typcially by the 5th to 7th bm, my melee themed base has electric fences, blade traps, turrets (both junk and electrical), shooting areas, ways I can utilize explosives and molotovs without catching myself in the blast radius/setting myself on fire. So I am using all aspects of base design to fight off the hordes.