I think pros tell players to play tight and good hands because they want them to learn the basics of the game first. They even explain the importance of good hands, position, etc. The more you play and know the game and is able to adapt to the table, you can open your hand range and play different styles. Look at Gus Hansen, he is a hyper-aggro player that'll play any two cards but he has a video out talking about playing position, playing tight, waiting for good hands in certain situations, etc. Its all basics.
There is such thing has a bad hand or playing a hand wrong, IMO, because there is no set rule on how you have to play. There will be situations against other players where you will want to play only big hands and other times where you can get away with playing marginals like 10/8s. It all depends on a number of factors: your table image, the table, type of game, the players, stack sizes, reads, etc. I usually play a TAG style. It just works for me and I have no problem waiting for my spots getting my money in. But then there are times where I am able to play LAG and change my style up and raise 60% of my hands PF. Its all situational.
With the Dan N hand. Was he in position? Was he getting good odds
to call? Who were the other players? Dans style is he is a bit of a loose-aggro, call station. He'll call with marginal hands like 10/8s, but if he flops something big he can take a lot chips off of his opponents. Sometimes it can be a bit hard to put Daniel on a hand.