The Magpies signed Thauvin from Marseille in the summer transfer window for a fee that Sky Sports valued at £12.85m, but the winger has struggled to make an impact so far.
The 22-year-old has quickly fallen out of favour in Newcastle's line-up, and Howey feels that he has shown a lack dedication so far.
"For me at the moment... miss. It's a lot of money for him," the ex-England international said.
"I watched Newcastle against West Ham. The first four times a camera went on him, he was messing with his hair. I'm thinking, 'why don't you just get on with the game and knuckle down? He just hasn't done it."
Thauvin was signed as a replacement for Remy Cabella, who failed to make an impact on Tyneside after joining in 2014, but there are already fears that his spell could be as unproductive as his fellow Frenchman's.
Thauvin's only goal so far has come against League Two outfit Northampton Town, and he seems to be struggling to make the transition to the English game.
Although the trickster has shown some flashy touches, his lack of strength and power has limited his impact on matches.
Steve McClaren will need him to find form soon, though, as Newcastle are in desperate need of their first win of the season, having failed to pick up three points from any of their first eight Premier League games.