they earned it fsu hasnt been impressive and while they have 2 good wins they dont stack up to back to back 15+ point wins over top 5 teams plus lsu was in the top 10 too so thats 3 top 10 teams in a row
while not impressive/dominating wins im pretty sure okie st and clemson are in the top 25 and every win over a currently ranked team counts for something
but yea msu is more impressive on offense and defense, has the more impressive wins, and so on
Same thing happened to them last season. It's Duke football and the reputation it (unfortunately) has among AP voters, coaches, etc.
They didn't break into the bottom of either poll until mid-November, when they reached 8-2 after beating a #24 Miami, and it became likely they would actual win their division...and that only got them to a 25 and 24 spot in the two polls (staying behind 4 or 5 teams that had already lost a 3rd game the next 2 weeks). They stayed there until they won their next two games, got to a 10-2 record, and then jumped up to 20th in each.
With the reputation that program's got, the voters/coaches seem pretty much just to treat it all as "Yeah, they're playing well...but they're Duke; they're going to fall back down to Earth soon."