I think it's an interesting demonstration of the rather sad fact that despite hardware today being many, many orders of magnitude faster than what was around e.g. 2 or 3 decades ago, it seems software has only gotten increasingly inefficient, so there's a huge amount of processing power and - if humans are being kept waiting, their time - being wasted because of this; this is a text editor, albeit a featureful one, whose resource consumption is disproportionate to its capabilities. It's what happens when countless abstractions are piled upon one another, with little regard for the consequences of doing such a thing.

Even Emacs is smaller, and it's just as if not more customisable/featureful.

Here is a nice rebuttal to that "premature optimisation" myth: http://ubiquity.acm.org/article.cfm?id=1513451

From personal experience, by the time a system gets too big/slow, the inefficiency is usually distributed throughout so that it becomes more difficult to single out one component that's causing it, and there is no easy way to optimise such a system short of redesigning and rewriting it - it can be said that the problem is because "the whole is bigger than the sum of its parts."