While Aldo was the FW Champion, there wasn't a single year he did not defend his belt.
Conor is already behind on this matter. He won't defend his FW belt for the whole duration of 2016 already. And he wasn't injured like Aldo, he was losing and rematching a replacement in a division neither belong while Frankie Edgar waited, smh.
technically, you're right, but he had a 13 months layoff between his bouts against Chad Mendes (January 2012) and Frankie Edgar (February 2013), then again a little more than a year between His second bout with Chad (October 2014) and his fight against Conor (December 2015)
Granted, these were due to some mishaps, injuries and whatnot, while Conor didn't defend but still kept fighting. I'd argue that at least Conor isn't shelved during that time and could, if he would, defend his belt. But each of his fight has broken attendance and PPV records, Aldo, really, was never a draw to the point of his skill level, for one who is in all the P4P discussions, he was actually not even in the main, but the co-main event at 3 of his 7 PPV appearances/6 title defenses, to GSP vs Shields (long gone from the UFC), Edgar (yep) vs Maynard (barely relevant anymore) 3, and Barao (has his ups and downs) vs Faber (in pre-retirement) 2
Conor is more active than Aldo never was, and each time he fights, the UFC numbers break records. With Jones doing whatever and Rousey being who knows where, Conor is of upmost importance for the UFC right now (and he knows it), as their only current and extremely active superstar, he is profitable and marketable like no other. Aldo, and I know I'm repeating myself here, wouldn't be bothered to learn at least some english.
At some point, the promoting has to count for something. I mean Aldo isn't really trying to sell himself, become the "money fight", while Conor is, arguably, making the UFC more money than they ever seen before.
Any company owner in his right mind would just milk that cash cow bone dry at this point. Most of the time, they try and save face, but at some level, Conor has to be running at least part of the show throughout the FW and LW divisions, should he keep winning (that's an entirely different story all together), that's the potential for History writing right there (even as for today, it's hardly arguable that McGregor has already put his mark on UFC history, whatever happens next).
Aldo should get his rematch, I agree, this would be fair
Conor should be stripped of the FW belt, I also agree, this would be fair
But while Aldo is sitting on his ass, whining and crying, Conor makes the UFC/Zuffa Millions, appealing to new, mainstream fans (without even starring in some B list action flick, he's not off half the year, Rouseying his way onto the big screen). Would you truly expect them to "punish" him or go against him? 205 is going to be a homerun, possibly the most stacked card of the year in a historical moment in time. Do you truly think they'll deprive themselves of their, by far, biggest draw, because it wouldn't be "fair" to some cry baby who had the potential to be a superstar but wouldn't be bothered? Ducked fights, barely fought once a year? Complained extensively and publicly about fighter pay?
For one butt hurt hardcore fan they'll lose with this fight instead of Aldo/McGregor 2 (most will remain and keep watching anyway), they probably get one full bar paying full on PPV bucks and exposing the show to dozens of new potential fans.
As far as the injury thing, we'll never know, maybe he's trying to get in Alvarez head, maybe we'll just never know, it doesn't really matter anyway at this point.