The problem with bloated website is, that the cumulative time lost while waiting for them to load is (for many) measured in many, many years. Pages like google/facebook/... optimizing load time by a couple of hundredths of a second, means years of real people time saved.
I know it sucks waiting for a website to load, but it's not like your life depends on it. You can still be an overall happy person while doing so, time is not "lost".
Performance metrics are better when put into perspective.
