Popeye and Bluto's fights can get fairly violent, whether they're using their fists or picking up weapons like saws, axes, and explosives. And Bluto and Popeye's affection for Olive Oyl isn't entirely innocent, either -- they often whistle at her, and they sometimes make some mildly suggestive comments as well. Then there's Popeye's pipe, which he smokes proudly (and sometimes puts spinach in -- which could send confusing signals), and several now-dated stereotypes. The earliest Popeye cartoons date from the '30s, after all, when portrayals of women (like the annoyingly helpless Olive) and people of other ethnicities weren't exactly politically correct.
All of that said, Popeye is still lots of fun. And the old sea-dog does promote eating your veggies (sometimes he and Olive Oyl will even make his nephews eat bowls of spinach instead of hot dogs and ice cream!). And, in the end, the show succeeds in sending the message that Popeye triumphs thanks to his good deeds, rather than any bad habits.