Rav Joseph Pearlman replies:

The Gemara does not in fact say that they did not want the final redemption to come in their lifetime. Rather, they said that they would prefer not to witness it happening. It could be that they meant that they did not want to participate in the cataclysmic events leading up to the advent of Mashi'ach, but just wanted to participate when all the hullabaloo was over.

Even if the Gemara is interpreted to mean that they would rather that Mashi'ach not come at all during their lifetime, the Gemara itself gives the reason that they felt they would not be able to endure the acute trauma, pain, and suffering of Chevlei Mashi'ach, the pangs of the coming of Mashi'ach (just as women often say that had men been chosen to be the ones to give birth, no children would ever be born, as the pain is so excruciating notwithstanding the ultimate reward).

Rebbi Yochanan here says the same thing. Perhaps it is comparable to his dictum in Berachos (5b), "Lo Hen v'Lo Secharan" ("I do not want them (the tribulations) and I do not want their reward"). Notwithstanding the fact that "suffering wipes away all of the sins of a person," and he would have had complete atonement for all of his sins, he preferred not to risk it in case he might not be able to accept the suffering properly, "b'Ahavah," with love, and instead of being his salvation, they may end up being his damnation if he were to be unable to bear them properly.

So, too, here, he did not feel sufficiently confident to survive intact spiritually the birthpangs of the devastating incipient Messianic era.

However, I much prefer the first explanation, that they wanted Mashi'ach to come -- "Yesei" -- but they would prefer all the preliminaries out of the way and out of their sight -- "v'Lo Achminei". This also explains the choice of words, "Let me not see him," rather than, "Let him not come until after I am gone." They meant, "Certainly, he must come now, but I do not want to witness it happening." In other words, "let me know when all the screaming and yelling is over, and then I will open my eyes to see the finished product."

Kol Tuv,

Joseph Pearlman