I wouldn't, shouldn't and will NOT defend Dembele against these gossips and accusations here.
But it seems some good folks here are getting a bit too easily influenced by the hype, and general tendencies against this young fellow.
Is he late for training? Perhaps, probably. Is it important? Yes, for the coaching staff yes, but not for the public. It's an internal matter whatsoever.
Is it important for how one judges the player? Not at all... How he plays is important, regardless if good or bad. Judge him by his actual contributions but don't let yourself be influenced by the press.
Is being punctual a merit that everyone needs to talk about when it comes to any player? Not our business and definitely not mine or yours.
Dembele looks to be, seems to be an introvert type of guy, probably constantly mucked in the green-room because of the lack of his language skills, but mind it that the young Messi was somewhat similar, with the advantage of having Spanish as his mother tongue. He couldn't learn even a word in English...
Let me tell you something.
When I used to play for my national team, there was a midfielder (who later passed 80+ appearances in the NT) who was ALWAYS late for any training.
But when he finally arrived, he was the most diligent guy in the team and we didn't really give a shit about his lack of punctuality. Neither did the coach or coaches, because all knew that this was just a week point of his personality, but as a contributor, he had always been better than anyone else.
When I used to coach a team in Asia (the same one that Del Pierro is coaching now) the best player in the team was always late, specially that he used public transportation only.
Undoubtedly he was the best in the team, so nobody really cared for his lack of punctuality. It was more important to have him there - even if 5 or 15 minutes late - because only his presence was what mattered.
That's why - if you really care for using your intellect - I wouldn't start repeating the gossips, using the gossips and accusations in order to prove your own agenda, because being late is a matter of discipline and we are not entitled to to enter into these matters. That's something that should remain internal to the club and management... What happens in the mile, stays in the mile...