I know people complain about too much gambling advertising on TV these days, but this is the perfect example of the utility of betting lines.
Cory Sandhagen has had 14 UFC fights. On the betting lines, Sandhagen was favored to win 10 of those fights, and was the underdog in 4 UFC fights.
Sandhagen in fact has a 10-4 UFC record.
Of those 10 wins, only one was an upset (against Lineker). Of those 4 losses, only one was an upset (against Dillashaw).
The fact is that Sandhagen has won 90% of the fights he was favored to win, and has only won 1/4 fights he was expected to lose.
Verdict: OP is objectively wrong.