I'm not sure about you, but the level of effort required to keep my emacs.d up to date and the level of effort required for each project has turned me away from emacs as my main development environment.
What are you doing with emacs.d that requires a burdensome level of effort to keep it "up to date"? What does that even mean? I've been using Emacs almost 10 years, and I very infrequently modify my emacs.d, and I don't know many people who do. Sure, I could spend a lot of time tweaking it and messing around with it, but it'd be an entirely self inflicted thing, and not the fault of Emacs. I could spend all day fiddling with .vimrc, or the Visual Studio settings, too.
I also don't understand the what you mean by "the level of effort required for each project" in the context of Emacs. What "project"s are you talking about?
I only started using emacs in emacs 22, so I haven't had to keep things working for 5-10 major releases like I'm sure some people have, but my init.el and .emacs.d have been pretty static the whole time.
(I also edit python in emacs regularly, not sure what's changed in the last N years)
I am not sure what you mean by "every tweak" but fwiw:
$ ls ~/.vim/bundle | wc -l
45
$ wc -l ~/.vimrc
401 /home/rahul/.vimrc
$ vim --startuptime vim.log
$ ruby -ne 'print if 2..7 or $. == 151' vim.log
times in msec
clock self+sourced self: sourced script
clock elapsed: other lines
000.810 000.810: --- VIM STARTING ---
217.536 000.003: --- VIM STARTED ---
In a week? 6 years and counting.