There are so many things wrong with this quest...

Let me explain:
Karma wise FO3 is very black and white...
This one is either very cynical (which doesn't fit any other documented quest) or just badly written.
In detail:
If I were to use the most peaceful option (all speech checks) The real bigots are the only humans to survive (they'll leave on their own accord). Every other single occupant will be slaughtered..
If one talks to Roy Philips he is shown to be as much, if not more so a [censored] than the tenpenny residents.
Even after finding out what Philips did... they see it as a minor mishap.. even threedog laughs about it.. WTF...
What is worse... He is still regarded as someone with good karma.. WTF #2

Now the bad option.. I can understand the true evil side of this quest (as Gingy explained.. killing TP residents yourself or let the ferals do the job), however the job itself.. ... is the game telling us that ghouls are better than people...? WTF #3

If I go back to my first PT... this quest actually made me angry, apart from the karma reasons..
If I do the "bad thing" I get caps...
If I do the good thing... I basically will activate a "cheat" which make me able to traverse dangerous grounds with ease. (after BS it became a blessing because you could avoid reavers.. *&%$##$!)

Just out of curiousity is it a scripted event for the the Tenpenny Tower residents to die by letting Roy in? What if through the use of modding or reverse pick pocketing or whatever you give all the residents in the tower Power Armor & Chinese Assault Rifles or Miniguns. Will they still all die? Do gouls just keep spawning till they do?

It's scripted... also if you choose the peaceful route.. you wont actually see the ghouls kill the residents.. They will simply be gone.... (you can find their remains though)

I remember when I went through all that work to get everyone to get along and to let the ghouls move in with tenpenny's residents, after I discovered what happened I killed them on every other playthrough i ever did.

Deja Vu

in real life i would have sided with the tenpenny snobs. but playing the game i hated the snobs more and let the ghouls in. best moment of the game imo.

This scenario has bugged me since I started playing Fallout 3.

As stated before its a lesser of two evils but with a definite liberal slant. You have the "ignorant wealthy" and the "underpriviledged discriminated poor" clashing. I get the feeling we are supposed to dislike the Tenpenny residents because they live in luxury and safety and are forced to empathesize with Roy and his followers.

When I tried to do the "right" thing many playthrus ago I was pisssed at the aftermath. Don't get me wrong the ghoul mask is very nice to have but I felt very bad at the consequences.

Nowadays I just sidestep the whole quest and bribe my way in. I love Tennpenny Tower and to me it is nice to have a little bubble of what was. (elevator music and friendly people/vendors dressed in 50's garb and cocktails)

In my view Tennpenny and his residence have worked hard to make their little slice of heaven and paid their dues. Roy needs to get off his ass and renovate another structure if he wants a nice place to live. (let him flip the Dunwich building and turn it into shangra-la if he wants real estate...its empty...now...your welcome Roy!)