I believe this is the reason that people sometimes go the other way and overly criticise Rooney. You'll have people saying "he has scored 30+ goals every season he has played consistently as a number 9", therefore "he is a World Class number 9" or as you have skewing his abysmal record in major tournaments for his Country to actually look incredibly impressive.
I'm sure if you asked Wayne Rooney he'd say there have been no excuses for his poor Euro/World Cup form over the years and he is working hard to improve that. I'm certain he wouldn't reply "well I actually score more than a goal/assist a game when I'm 110% injury free, have had a run of good form in the lead up and am played in a specific position of my choosing, oh and it has to be on a Sunday at 4pm".
The fact is Rooney is a very good player, nothing more, nothing less. If you are expecting performances at the consistency of player's like RVP, Hazard, Suarez, Ibrahimovic, Robben, Bale, Toure, Ribery, Aguero etc you are going to be disappointed. No one expects the likes of Muller, Benzema, Cavani, Lewandowski etc to single handedly carry a team, they merely expect them to put in good performances. Rooney is held to a higher standard than other "third tier" player's because people think he's in the "second tier" because of his name and salary.
It's like expecting Aguero to be Messi: even though the former is a great player, you'd always be disappointed.