Not true. Yahoo! is presenting the results which offer the best profits - specifically the previously monetized Inktomi PFI index that has been rolled into the new Yahoo Search Technology.
ATW = better results
YST = better cash flow
This is all perfectly within their rights. They obviously also bear all ramifications.
I don't think many here realistically think Yahoo! should support three seperate search engines in a commercial sense. I think some are just lamenting the fact that the superior product is the one meeting its demise. However, this isn't the first time (or last) this has occurred in the IT/software, etc. industries.