I would agree with that. The only thing I will say is adjectives like 'suck', 'good', 'bad' etc are all subjective. A player you might consider good I might say is above average. With that being said Kemp has proven to not even be an average player statistically the past few seasons. Right now he is playing at a level that is better than average but of course there is no guarantee that continues through the rest of the season.
I didn't watch Kemp when he was with LA or SD. Maybe injuries or bad conditioning impacted his game. Maybe it was a degredaton of skills. I'm not sure. I don't think you could only look at his status sheet and make the determination. I'd be more comfor table with an approach of evaluating the Statline then watch film with the premise of figuring out why he was bad. Do you see the distinction I'm making here?