With Lin, he tended to post big numbers against big name out of conference opponents, then recede somewhat in league play. With the best players in the Ivy League sticking around for four years to get their valuable diplomas, in contrast to big time college ball where one and done is the norm for top talent, the quality of Ivy League regular season play might now be a lot higher than is assumed.
Before the best players could go to the NBA early, conference play was hard because the same players met year after year. For example, the 1969 UCLA Bruins, with senior Lew Alcindor / Kareem Abdul-Jabbar (the future all time NBA scoring leader) leading them to a third straight national championship, was one of the best teams ever. Going into the last conference home and away series against USC, they were 84-1 with Alcindor, losing only to Elvin Hayes in the Houston Astrodome when Alcindor was hurting. But USC took them to overtime at Pauley, then beat them the next night at the Sports Arena. How? Well, the Trojan players had been thinking a long, long time about how to beat Alcindor and the Bruins. Similarly, by his fourth year, Lin's Ivy League opponents probably had better ideas about how to defend him than the Lakers had.
Also, keep in mind that Lin wasn't really a point guard in college, he was more like a Best Player on the Team guard, like a Harvard version of Michael Jordan. He didn't have any success in the pros until he was the best player on the team again due to problems with the Knicks.
I think the weird thing with Lin is that everybody still expects him to be a good role player and teammate because he's Chinese, and everybody is tired of self-centered black players like Carmelo Anthony. In the post-Obama age, lots of people have gotten tired of waiting for their dividend from electing Obama in terms of better black behavior, so they are seizing upon this Chinese guy as a role model to show up blacks with his team-oriented play.
But the evidence so far is that Lin does best, like against the Lakers, in Gimme the Damn Ball and Get Out of My Way situations. As a basketball talent, he's less like Derek Fisher and more like Allen Iverson.