I'd say that Google has more reason to be suspicious than Webmasters do, because Google, like other search engines, is giving away a valuable commodity--free traffic--in return for indexing Webmasters' sites. Many Webmasters, on the other hand, are interested only in taking. (What public good is served by click arbitrageurs' sites, made-for-AdSense sites with scraped search results or borrowed Wikipedia and DMOZ content, boilerplate affiliate sites, and other sites that have no intrinsic value for users?)
It's important to remember, too, that complaints about the dominance of Google (or any other search engine) are most likely to come from those who aren't happy with their search rankings. Misery loves company, and in some cases misery demands company. We wouldn't have threads like these if everyone got to be in the top 10 search results for "widgets" or "whatsits" or "elbonia hotel bookings."