While I would also personally prefer this functionality as an extension rather than as "bloatware" (although it's not exactly useless), I believe having it built-in will better the majority of Chrome users who are not savvy (or aware) enough to install extensions, which as of Dec 2010 was only 1/3 of Chrome users (the most recent stats from Chromium I can find) [1].

[1] https://blog.chromium.org/2010/12/year-of-extensions.html