Google bought it in July 05, one year after IPO. The smartest phones available were the Blackberry 7750, Motorola Q, and Palm Treo. Google had $3B in revenue in 04 and was on its way to $6B in revenue in 05 when it spent $50MM on Android.
There was no way this acquisition would have been blocked without clairvoyance. Even then "stop this $3B company from buying a startup because it's going to destroy a $35B company in 9 years" is not exactly a compelling argument.
The argument is even more nonsensical than that against Facebook's Instagram acquisition, which is saying something. People argue that DOJ or FTC should have stopped a company that hadn't yet IPOd from buying a company that had raised $7MM (and would raise $50MM a few days before the facebook acquisition).
Sure they're obviously huge in retrospect but they really weren't at the time. Interesting and hot companies die all the time: YikYak and Secret looked like they were going to take over the world at one point.