The Gemara in Sanhedrin 108 relates the Machlokes between Rebbe Yochanan and Reish Lakish. Rebbe Yochanan stressed the ‘Bidorosav’, that in another generation he wouldn’t stand out, while Reish Lakish said that if in his generation he stood this much above them, in a better generation he would have surely reached great heights.
Although both can be true, the question is what the emphasis of the Pasuk is.
Additionally, the Machlokes here is about who Noach was and how he got there. According to Rebbe Yochanan, Noach was a person who was able to withstand great temptations in the face of all evil. This was his greatness. In a better generation he would not shine. His essence would never have a chance to make its mark. He was placed in the right generation for him to fulfill his task. This is not necessarily a derogatory statement. It is rather a description of what he is about, and where his greatness lies.
Reish Lakish says that Noach got where he was by climbing the ladder rung by rung. He rose above his generation. Had he been among better people he would have been able to climb even higher.
If we take this a step further we see another Machlokes, in Brachos 34b. Rebbe Yochanan says that Tzadikim Gemurim are higher than Balei Teshuva and Rebbe Avahu says that Tzadikim can’t stand in the ranks of Balei Teshuva.
So, this is sort of Leshitaso. Rebbe Yochanan saw the concept of Tzadik Gamor as the highest level. This is how he described Noach, as unbending and pure. Rebbe Yochanan himself had this Middah (as we see on Daf 19 that he refers to himself as a descendant of Yosef). Reish Lakish was himself a Baal Teshuva, and he saw the greatness of being able to rise above yourself. He describes Noach as someone that rose above the situation.
Yosef too, had the greatness of withstanding great temptations of evil and of standing firm and unbending. At his father’s house his greatness was not recognized and he was looked down upon. However, in Mitzrayim his greatness shone. Klal Yisroel needed him to be there first to be an example of how to live amongst the Egyptians.