Yahoo/Bing is different from Google, not necessarily better or easier. If you have a good handle of their algo then focusing on Yahoo/Bing can be profitable.
I know some arrogant webmasters who thought they were SEO masters since they knew a few short term tricks in Google. They falsely thought ranking in Yahoo/Bing would be no problem. Those webmasters quickly realized they were not SEO masters and had ranking troubles in Yahoo/Bing.
Make sure you are basing your decision on facts & not emotion.