Google the most relevant search engine? Not all the time

I’ve been checking some results pages on some terms that one of my clients targets, and was somewhat dissatisfied with the results that Google returns on these terms.

The phrases that I have been looking for here specifically were:

Alternative to cosmetic surgery
Alternative to plastic surgery

Looking at these terms, its quite clear that the searcher is NOT looking for cosmetic/plastic surgery, and the results displayed on Yahoo and MSN respectively seem to reflect that, with a few exceptions:

Yahoo:

MSN/Live:

However when it came to searching on Google, it seemed that a lot of the results being displayed were for cosmetic/plastic surgeons. This baffled me somewhat, as the search term is clearly suggesting that the user isn’t looking for someone to perform this type of procedure, and is looking for an "Alternative" – with this being a core word within the phrase. The first 2 results are relevant to the term, but most of the others on page 1 were not:

After going through some of the results pages, I noticed at the bottom of the second page a reference to the fact that that the phrase "alternative" was not actually being used in the results:

I can’t really understand why Google are doing this on this phrase. You can revise your search to include this word (putting a + in front of "alternative"), but it seems that this is an area where the searcher intent is not being properly understood and you aren’t told about the phrase alternative not being used in the results until the bottom of page 2. These results make it particularly difficult to try and do some SEO work on these phrases, as although the searcher intent is clear, it is being ignored to some degree by Google.

In this case (and it is admittedly quite rare), it seems that Yahoo and MSN are delivering slightly more relevant results to this search term than Google. As a result of this, I’m not sure if there is value in continuing to optimise my client for this phrase, as if the engine with the largest traffic potential is not returning results that are relevant to this term, then there is little value in continuing to optimise for it.

There were some results in all 3 engines for plastic surgeons on these terms, but Google seemed to have a lot more of these at the top of their results pages.