I do think that rather too much emphasis is being placed on some of the lower-end twins.
I went out practicing for my IR/MEP renewal last year in my Aztec E and took four large friends with me. At least three of the five of us were rugby player types, two others were smaller, but adult. We had full tanks, but no baggage. I calculated the weight as being about 140lbs under MTOW.
On a moderately cold day (ISA -5) and everything handled according to the book we climbed at 800fpm from 250ft after a simulated EFATO.
We executed two go-arounds from 250ft and climbed perfectly well. By the time I had burned an hour's fuel and honed my technique, we were closer to 900fpm.
I believe that at least two of the pax are on this forum and can stand witness.
Pilots need to take responsibility for knowing the performance of their aircraft. I agree with everyone that I would be very nervous indeed in a Seneca I, Twin-Comm or Cougar at or near MTOW, and indeed agree that these are singles with their engines split in two, but once you are looking at aircraft with excess power (PA31, C4xx, PA23-250 etc) the whole business of SE operation looks rather more rosy.
There is another factor which no-one seems to have mentioned. Days with 250ft cloudbases on the whole tend to be cold, which is helpful.
So I suppose I am saying let's not generalise with too many sweeping statements, but try to encourage twin pilots to learn about their aircraft, be observant about their immediate circumstances and take the best decision in the prevailing situation.