Honestly this is the movie with all the hype and expectations to uphold to the Lord of the Rings trilogy (which any sensible person who has read the books would know this would not hold its own against the Lord of the Rings), so the critics seem more disappointed it does not uphold to the Lord of the Rings than they are saying that its a bad movie (no critic has actually said that). And the main critic (besides the unjustified 48 fps one) is the slow start which was true with fellowship and material that felt out of place (which ties in during the future two movies). I honestly I expected this one to have the lowed ratings same as Fellowship did. I would expect the next two to get better ratings and improve on each other (like the Lord of the Rings did). I would not be surprised to see Desolation of Smaug be in the 80% range and There and Back Again the high 80 to low 90 percent range.
Don't like the 73% and 25% delude you it's a 7.3 average and nearly a 7 average for top critics, a 7 is a good score (movies such as Gladiator, Wreck It Ralph, Iron Man, Forrest Gump, and Braveheart have similar and in Gladiator, Braveheart, and gump's case, lower scores). People are really misinterpreting these reviews as saying the movie is garbage when really what they are saying is the movie is good just disappointed critics when comparing it to Lord of the Rings.