It comes back to the old conundrum for providers of a product (e.g. car insurance) as to whether or not to be listed on price comparison websites. If you believe the comparison website is puny, and the insurer has a large market presence and brand recognition, it is often not worth the insurer showing product quotes to the comparison website.
Once the price comparison website becomes all powerful, the insurer is on much less certain ground.
If Ryanair won't say no to Google, you can put on all the spin that you like, but it says to me that either MOL is worried or someone is twisting MOL's arm