Both aircraft are good depending on the needs of the airline. I have a friend who works for Bombardier and he says the selling price for each aircraft is so ridiculously different depending on the customer, that they basically make no margin on majority of the aircraft they sell. They make their money after supplying maintenance, training, and service to their aircraft.
CEO's of airlines don't just favor one over the other, it all comes down to the economics of what the airline wants to achieve per passenger, and delivery date among many other factors. The cost efficiency of one aircraft may be better than another but lets say you need 1 aircraft per year guaranteed at similar price and one manufacturer could deliver it sooner than later, that changes your cost efficiency already!
I.e. Air Canada chose 737 MAX's over A320neos (after being an airbus user for decades) because when they initiated their fleet renewal program, Airbus couldn't provide the aircraft when they wanted.
Same thing occurred a few years back when AC was renewing their long range fleet, Airbus introduced the a380 which didn't fit AC's requirements, so AC went with the 777 and 787. Now in the future they'll have a focused Boeing fleet, which means more efficiency for their engineers and technicians.
It would also be wise to consider the fact that most accidents on either aircraft and human error related, not aircraft issues. Yes mechanically the 737 has had its fair share of issues but the next generation of both aircraft are sound.
You could go to any airline and they'll give you different opinions, my take is respect each and if you're a pilot, fly what you're rated on well!
Last edited by striker26; 24th Jul 2015 at 20:17.