If Jesus had scored the offside goal Aguero did, there would be pandemonium in here.
However, the reason Aguero was offside was because he was playing on the shoulder of the last defender, which is something he rarely does these days (normally we see him stay just onside and look to get the ball into his feet as opposed to on the run). It's an incredibly high risk, high reward strategy, that requires BOTH perfect timing from the attacker AND perfect timing from whoever is playing the pass. We've seen countless times over the years, that being a fraction of a second too fast or slow can be the difference between a perfect run and offside. Aguero just fell on the wrong side of it last night, but you can be sure if he played like that more often it'd happen more often too.
My point being is that it's just part and parcel and anyone can do it. Aguero's brilliant and if he were offside 3 times a game playing off the last defender I wouldn't question his talent. It's the same with Jesus; there's a reason he's offside and whilst obviously he has work to do it's just part and parcel of his style of play.