The M1 Carbine had a good reputation in the Pacific theatre as the ranges were in relation to the design of the rifle. The problem is when people started to think that it would work past its effective range. If those same people were to use a Grease gun at those same ranges, they would get the same results. If you were to try to make the Garand an anti-aircraft gun, it would not be very successful either.
The real bad reputation of the Carbine was in Korea. This was due to two items. The first is the M2 version of the Carbine. And the second was the long ranges. Carbines were used at 200-500 yards regularly. The results were dismal. This should be expected as the round and the rifle were not designed for this purpose.
The addition of full auto fire made things worse. The most common war story of people that used the carbine was that they emptied a full magazine and the enemy did not seem effected by it. If you have any experience with full auto carbines you will notice that there is considerable muzzle rise. What happened was a soldier shot at an enemy over 200 yards away, the muzzle rise caused the rest of the rounds to miss and the first round did not hit due to the range of the engagement. So the enemy was not hit at all. The carbine is a very effective round when used as the firearm it was designed. It is meant for 150 yards and under use. Full-auto fire is for 50 yards or less. In this role it is highly effective and its reputation in this role has been proven.
The 1911 is a good handgun when used by a competent shooter. Its accuracy reputation is from handguns that were not maintained correctly while in use for 30-40 years. Most of the people that could not hit were using handguns that had been passed on to the next recruit every 8 weeks or so. That promotes wear as each recruit has to learn how to tear down, assemble, CLEAN properly, and then shoot it.
As for the 1911 needing a lot of tuning for accuracy, that is only for competition as does the M14, Beretta M9, M16, and every other competition firearm. The M1 Carbine functioned well, was accurate enough for its intended role, and is more effective than most submachine gun rounds. If it was as bad as some of you say it is, then it would have suffered the same fate as the Reising. It would not have been produced into the 1950’s. It would not have been copied for civilian use. It would not be used by the Israelis even to this day if it were such a terrible firearm.