Don't be a jerk -- Googlers posting in forums like that do this for good reason. All Googlers take mandatory training and among those mandatory training courses are all sorts of notes on how not say things in public which could be construed as reflecting on the company. Making it clear "opinions are my own" is CYA, and a completely reasonable one for people who want to keep their job.
(Ref: Used to work at Google. No longer have to cover my ass.)