If ask.com and bing.com move out of the search space or turn off the lights (hypothetically), then those are two fewer companies competing with Google and driving their innovation. If you have many companies in the field, this isn't a huge deal, but search has (as far as I can remember) been dominated by a few giants, had a high barrier to entry, and seems to be shrinking every year. In this case, the market has done some good, but Google could always create a better search product - and if they didn't, then we would need competitors to do it.

"The free market system is working" really isn't a very nice response to "our company is desperately trying to maintain a revenue stream" (which is probably an exaggeration of ask.com's current financial situation).