Less is more, more or less
The basic premises of Minimalism as an approach to software development are to write as little code as possible, to leave everything with the default settings until a change is needed, and to defer adding any features, functions, UI elements, validation or anything else not explicitly defined in the acceptance criteria, wireframes, visual designs.
Commonly this is mistaken for lazy, but takes an incredible amount of hard work and dedication to achieve. It’s always tempting to add-this-to-that, refine-this, and defensively code to protect against conditions that can never happen.
Leave it alone
If you can avoid changing something, it’s generally better to avoid changing it. For example, it would be fairly straightforward to create a CSS pre-processor just for correcting the horrible and ugly incorrect spelling of ‘color’. Unfortunately we are stuck with this mistake universally across all web browsers and will have to live with it, and creating something that allows us to code with the correct spelling of ‘colour’ would be nothing more than code for codes sake.
Another area where this applies is system defaults. If you don’t have a value-driven reason to alter something then leave it alone. Optimisation is another area where this applies, particularly with JVM options and garbage collection settings. Just leave it alone until forced to make a change.
Unless you have a reason, it doesn’t matter
for a code-minimalist, the only legitimate reasons to make a change have a quantifiable business value in the form of cost savings, increased revenue, or improvements to the development turnaround that outweigh the effort to make the change. Without this, it’s unwelcome code.
Seriously though, there are things you need but are far too easily missed from the requirements. Security is often a casualty, and so can performance both in terms of scalability and concurrency. Functionality takes priority as it’s easier to rationalise.
Design can suffer from this when constrained to a framework like Bootstrap, but this seems to be less of a problem as most designers seem to conform to the 960px 12-column grid.