Because if you miss three releases then you have to do three upgrades. If you setup a system and then come back to it a couple of years later and find you need to upgrade you can plan on fighting through multiple system braking upgrades. Yes I know you can mitigate this with LTS but that's a big compromise.
I told him I haven't installed a new OS on my primary PC in 10 years. I just DD it from one drive to another.
DD is by far the easiest way of making bootable media on a flash drive as well. I use that method to create install media for my other computers.
Genuine question as a Ubuntu user, where do you win using Debian on a laptop? I totally understand using it on servers, as it is the definition of 'rock solid' and you can ensure that it will work 100% of the time.
Admittedly I don't pay a huge amount of attention to the differences, but isn't using Ubuntu LTS compromising in the same way as Debian stable? Specifically, packages are oriented for stability. Consequently, you don't get improvements to the kernel, or other packages you may use frequently. On my laptop, I don't want to use Kernel 3.6 that doesn't have the latest improvements to work with Intel processors, direct rendering management, and power saving. I don't particularly want to use quite outdated versions of GNOME either. Six months, to me, is a solid amount of time to sit on a release.
Some people suggest (misguidedly, according to Debian volunteers) using Unstable on a workstation / laptop, which caused my system to outright break entirely because I was using a Nvidia graphics card, so I just installed Ubuntu and it worked from first boot.
Using testing is sworn against by almost everybody, as it's the worst of both worlds - it's not stable and it's not fixed quickly.
Stable plus backports, suggested elsewhere in these comments, sounds nice only if you consider ensuring that water drains out of each hole in a colander equally an adequate use of your time. You then have what I'm fairly sure it's explicitly listed as "don't do this" on the DontBreakDebian[0] page.
There's something to be said for running multiple distributions so you spot binaries in different places, etc, but really running the same system "everywhere" has more value to me.
My laptop/desktop run Debian stable, my servers run Debian stable, and so I know what to expect.
When I need things that aren't available, or have to be backported, I know how to do that. For extreme changes I can use containers, or virtual machines. But for the past few years I've not been convinced in the feature-churn or value added by Ubuntu. (Especially when you see that their "universe" isn't really supported by anybody - hell even looking at bug reports for their supported packages is often depressing. Bugs open for very long time with no updates because of lack of people willing/able to fix them - combined with forum advice which is often the blind leading the blind.)
Nonsense. Testing is stable and up to date. Ubuntu is based off of testing. Debian's rolling release system makes upgrades easy.
Why? You shouldn't rely on system files for development... you probably want a proper dev environment that can later be replicated into production or staging (eg. containerization, VMs, virtualenv, etc). Just stick with Ubuntu LTS releases, and enjoy the consistent updates (eg. security) and the massive support benefits (eg. forums) associated with running one of the most popular distros.
Personally, I love the consistent Ubuntu updates. Granted... I always switch to xfce for the desktop environment.