I just love how people use "legendaries" as a synonym for "ubers". Articuno sucks. Moltres sucks too. Zapdos isn't any better than Jolteon or Electivire. Entei sucks. Suicune is alright, but it's not really much better than Vaporeon or Milotic. Raikou is just a crappier version of Jolteon that can Calm Mind, a move I'm sure most of the people on this forum don't bother to use. Celebi and Jirachi aren't even that strong. Neither are the Regi trio. And certainly not Phione. Manaphy is only strong in rain, but that means either using Kyogre or Rain Dance, which takes up a turn and isn't really even worth it. There are plenty of Pokemon stronger than all of the ones I listed (barring Kyogre), so would it be cheating to use those?
Using legendaries =/= using ubers. Neither is technically cheating, but I guess you could say that using ubers is cheap and weak.