Yes, the winning percentage will keep Pelini around a long time. The reason for the "comparisons" to Osborne are more about what happened during Osborne's tenure. Osborne struggled to win the conference title in his first decade. Osborne was chatting with Boulder Colorado realtors in the late 70's......ironically around his 7 year mark. And yes, Osborne did suffer blowouts. Two of them to end the 1990 season......year 17....yikes!! Osborne's ultimate legacy is because of his last five years. In many ways, his first 20 years had their share of "struggles".
The only way these Osborne comparisons survive is by being incredibly vague. Once you bring up the actual detailed facts, the absurdity of them gets exposed pretty quickly.
In his first six seasons, Tom had four losses by more than two touchdowns (15+ points):
@ #3 Oklahoma
@ #7 Oklahoma
@ #3 Oklahoma
@ #1 Alabama
In his first six seasons, Bo had ten losses by more than two touchdowns:
vs. #4 Missouri
@ #4 Oklahoma
vs. unranked Texas Tech
@ #7 Wisconsin
@ #20 Michigan
vs. #10 South Carolina
@ #12 Ohio State
vs. unranked Wisconsin
vs #16 UCLA
vs. unranked Iowa
In his first six seasons, Tom played 25 teams ranked in the AP Top 25 (34.2% of his total games were vs. ranked teams). His record was 15-10 (60%).
In his first six seasons, Bo played 23 teams ranked in the AP Top 25 (27.7% of his total games were vs. ranked teams). His record was 9-14 (39.1%).
In his first six seasons, Tom finished in the AP Top 10 five times. (The other year he finished 12th.)
In his first six seasons, Bo finished in the AP Top 10 zero times. (His best finish was 14th.)