Why do you keep talking about Messi? We're discussing CR7.
I think the comparison with L.Ronaldo is a little disingenuous as well as Serie A was comfortably the best league in the world back then and he only had 1 full season before getting horrifically injured. Despite that, during those 5 years he had a goal every 112 mins - in the same time, the second best striker Batistuta had a goal every 153 mins. CR7 is battling it out with Immobile, Lukaku and Quagliarella in a much weaker version of the Serie A.
Well Its surely is a case of double standard here, hence its best to just give examples and applying same standard to other players, one will then find how ridiculous the criticism was. Messi is an easy reference because he is of similar status as Ronaldo (high wages, high expectations, great individual stats, but didn't win as many trophies in past couple of years).
As for L.Ronaldo, well now you are demonstrating another examples of double standard here, comparing goals per mins of LRonaldo during his time in Italy to defend his status, while ignore the same for Ronaldo during his time in Italy (where he is by far the best in total no. of goals, or goals per games etc). Also, during L.Ronaldo first full season with Inter, he loss out to Biehorff, other seasons he was injured, so he can be excused there. Then in Real Madrid, over 4 full seasons, he lost out Pichichi to Makaay, Forlan and Etoo. But no one really cares to mention any of that. Yet we have bunch of people here criticising Ronaldo not winning 2 particular Capocannoniere in last 2 seasons, despite outscoring everyone there by a distance over the whole period of time.
Look, 79 goals in 94 Serie A games, 99 goals in 129 games in Italy, 117 goals in 148 games in all competitions over past 3 years, thats in average around 40 goals per year in all competitions. And we are talking about a player during his 33-36 years of age. In any other era of football, that will be highly worshipped and praised.
For better perspective, here's total output other GOAT or all time greats during their 33-36 of age:
*Ronaldo: 117 goals in 148 games (one of top league, still counting)
Puskas: 115 goals in 124 games (one of top league)
Di Stefano: 90 goals in 131 games (one of top league)
Pele: 81 goals in 141 games (41 of those from US league)
Muller: 38 goals in 84 games (35 of those from US league)
*Messi: 36 goals in 44 games (up to now at 33 years of age only, will be 34 next month... and 2 more years to go)
L.Ronaldo: 35 goals in 69 games (all from Brazil league)
Cruyff: 30 goals in 87 games (all from US league)
Eusebio: 24 goals in 67 games (US league/Mexico league)
Zico: 13 goals in 41 games (Brazil league)
Law: 12 goals in 36 games (one of top league)
Maradona: 5 goals in 31 games (all from Argentina league)
Best: 5 goals in 41 games (US league/Scottish league)
Garrincha: 4 goals in 19 games (Brazil league)
Most other GOAT or all time greats couldn't even match one third of Ronaldo output at same age at top level, and that's speaking from the perspective of football history as a whole. Yet in here, we have group of fans here who will not stop criticising him even for his output at that age. That's quite pathetic.