Let me add this - you look back now and can say, "Carter was a good guy and not a great President, Reagan" - well there's variations of thoughts there.
But in 1980, look at the candidates:
Reagan - no explanation necessary
Bush 41 - former Congresscritter, Ambassador to China, CIA director, party chairman, great war record
Dole - Senator, highly influential in his own party, great war record
John Anderson - maverick liberal (even for that time), helluva great debater, old school GOP, great war record
John Connally - former Dem turned Republican, kinda viewed as a shady TX guy, got shot with JFK
Howard Baker - Senate Minority Leader, moderate, the guy who asked "what did Nixon know and when"
Phil Crane - hard right guy from Illinois, known as "the Kennedy of the right"
Jimmy Carter - former GA governor, President, peanut farmer
Ted Kennedy - long-serving Senator at the time, member of the most famous political family of the time
Jerry Brown - CA governor who was all over the place, not really liberal but not really conservative (Brown had no political core other than "I should be in office")
So there you have 3 (eventual) Presidents running of varying success, another guy who won the nomination and lost (Dole)......and what did the voters and press of the time say?
"We don't like any of these candidates, and we wish someone else would run"
Other than Crane (who was the best debater not named John Anderson on the GOP side) and Connally's shiftiness, that GOP field was probably the best one they ever produced in terms of qualifications.
And it still wasn't enough for some people. Reagan is an extremist who'll start WW3, Bush is a wimp, Dole is mean, Anderson is too far to the left, Connally is a crook, etc.