See the thing which IMO goes against Cristiano is Messi has as much goals as Cristiano while also having things which people use as a measure for player comparison especially when comparing attacking players. The technical stuffs like passing, shooting, crossing, heading, dribbling and finishing and than the mental stuffs like tactical awareness, vision, creativity, ability to perform under pressure, big stage composure and so on. Cristiano is mostly equal to Messi in terms of goals scoring and assists statistics, while being better in heading and recently has performed better at big stage(although until some years Messi was leading, but let's give Ronnie his due).
But other flashy stuffs and Messi being a passer, play maker, dribbler and goal scorer all in one, that too all time quality, tends to catch attention of most football romantics. Obviously those who rate results over this romance find it disgusting that why people go gaga over Messi while dissing Cristiano for the same.
EXAMPLE:
Cristiano scores hat trick while combining well with his teammates, running hard, getting in good position all night and than scoring with 10 shots, while Messi also scores hat tricks with 10 shots and he also some good looking dribbles, passes and combination plays with teammates.
Statistically there is not much difference as both scored 3 goals from 10 shots. Messi's dribbling, passing and combination plays did create chance but they did not create any goals. So when it comes to pure statistics no difference as at the end of the day both scored 3 goals.
But why reactions are difference?? Cristiano's performance will be praised but Messi's performance will be worshipped. It is simple football fans rate some stuffs more than just results. There is a reason 1982 world cup is known for the Brazilian team which lost while winners Italy are always sidelined. Same with Messi Cristiano, and unlike Italy which beat that Brazil, Cristiano has not won against Messi, they are equal, hence many people praise Cristiano's determination but refuse to call him better than Messi. Results wise he is as good, but other stuffs(no matter how useless he is behind Messi.
That is the best way I can explain why Messi gets over hyped while Cristiano is not as worshipped as him by most folks.