Not true the Packers only had losing seasons in 1990 and 1991. 1992-1999 the worst season they ever had was 8-8 and that was in 1999. 92-94 they finished 9-7, 95 11-5, 96 was 13-3, 97 was also 13-3 and 98 was 11-5.
I wouldn't say illegal but it was somewhat dirty.