If you raise it up pf and get the pot heads up and miss completely your AQ high might still be good! That way if he misses completely you can make a c-bet and take the pot down easily. If you let 6 people in the pot you have to play hit to win and even if you hit your ace a guy w/ A9 could hit 2-pair against you etc. Much lower risk to limit the field and get that min-raiser heads up. Also, raising would create a much bigger pot and players tend to get attached to a pot once it gets big. This would give you much more action once you do hit a monster flop.