The sole purpose of this castle is to keep Mario out and keep Peach in, so I want to know which motherfucker working the front gates is just letting Mario in. There is no Trojan Horse trickery going on here - Mario walks to the entrance in plain sight, LOOKS UP as if he's greeting the doorman to his building, and then is let in. You'd have more trouble getting into a club on a Saturday than Mario does getting into this castle. Yoshi is strictly not allowed though.
This just doesn't cut it for me, Bowser. In the NES Super Mario Bros, you have an axe readily available upon the entrance of your only enemy, so why are you not going to pick it up and start swinging? Does jumping and shooting fire really have a higher success rate than decapitation? Not only do you not use it, MARIO does. Your enemy. Repeatedly. After the second time of falling into a fire pit by the hands of your own axe, I gotta recommend using it or losing it, big guy.
For someone who is regularly captured and imprisoned there, Peach sure has few to no reservations about squeezing in 18 holes of stroke play, doing some 150cc racing, or playing some doubles tennis with the gang. Maybe it's because she's completely resolved to the fact that her life will be a nonstop series of kidnappings and she has decided, "Well, fuck it. Hand me my 9 iron."
In Mario Kart 64, you are welcomed into Bowser's Castle by a symphony of angry blue thwomps grunting and pounding down a long corridor. On display like a hunting trophy at the very end of this hallway is a grumpy GREEN thwomp, imprisoned. He looks exactly like all the other thwomps, save for the fact that he is green - which makes me think there's some seriously RACIST shit going down at Bowser's Castle.
Whenever Mario bests one of Bowser's castles, Bowser just leaves that castle and creates a new one not too far away. Bowser "hits and quits" extremely expensive, massive stone edifices, and so do all of his little children. That leaves the Mushroom Kingdom chopped full of abandoned castles, with still operational traps that run 24/7...for no one.
I'm not clear on if Toad was captured with Peach, or if he just kinda kicks it in Bowser's Castle all the time. When you run into him, he doesn't immediately shriek, "OH GOD THANK YOU I THOUGHT I WAS DONE FOR", which is a good thing, but makes me think he's straight up squatting in Bowser's Castle, hitting the fridge on the reg and pounding brews til Mario gets there.
In Paper Mario 64, Bowser's Castle lifts up from the earth revealing a creepy yellow clown face on the castle's underbelly. A similar looking face is more often seen on The Koopa Clown Car, but functions the same way in that it will transport Bowser and Co. wherever the fuck they want. This spooky carnival grimace is able to "change its expression" which makes me think it is alive and very much a slave.
There is not a single comfortable, decorative, or remotely livable thing within this castle - the whole place is just a bunch of traps. No couches. No televisions. Never once seen a bathroom. The man lives in an episode of Wipeout! What is it like to live in this place when Mario is not around? There's 0% chance Bowser ever entertains house guests here because instead of hardwood floors there is fucking magma.