Ah, well... rather innacurate. The Romans did suffer the defeats you mention but despite those defeats, the managed to carve the largest single empire until the Mongols got the stick in the 13th century.
That, by itself, is an admirable fact: Rome was just a city-state, starting from a backwater locale in central Italy (the "center of the world" at the time was located in the eastern mediteranean) and managing, over a course of a few centuries, to create a huge, stable, progressive, greatly administered empire. The real strength of Rome didn't lie with the (admirably effective, although you belittle them a bit too much) legions, it lied within the publicum Romanum itself. The Romans got trashed three times by Hannibal, their manpower exhausted... any other city would succumb to its fate, but not Rome. They came back and a few years later razed Carthago to the ground and started building their empire.
Compare that with, say, the Mongols. Great warriors, ruthless, swift, effective - unstoppable. Their empire lived... how long? 100 years? And what's the legacy they left to humanity? The 2nd greatest murderer of all times (Chinghiz Khan) and... the yurt.
What did the Romans leave? An Empire that lasted (if we add it's eastern reincarnation) for 1600 years, a host of Roman-derived languages and cultures, the best legal and administrative system until the industrial revolution, the basis for the "Western" world...
...all in all, quite a record for those "lousy warriors"
Edited by Romano Nero