Having a high k/d does not make you a good player. A very low k/d is a pretty good indication of a bad player, however.
A high k/d means that the account you are looking at has had notably more kills than deaths since creation or the last reset.
Having a high k/d COULD indicate a good player insofar as team deathmatch is concerned. Then again, if you're camping and playing it safe, you may have a 3.0 k/d from 3 kills and 1 death every game- this is a high k/d but you aren't a good player even in team deathmatch.
If you set a threshold k/d for yourself and dashboard whenever you dip below it, you could have a high k/d and be an AWFUL player. With time, effort, and a LOT of dashboarding, ANYONE could have a high k/d in theory- Lets say you want a 10 k/d and you just reset your stats. Play each game shooting for 10+ kills and 1 death or less. Dashboard if you die a second time before hitting your 10th kill. If you go 10 and 1 or 10 and 0, leave the game normally at that point or hide until it ends. Particularly bad player? Maybe just try to score 1 kill without dying in every game and dashboard if you die.
That said, even if you can't assume a good player from a high k/d, you can in most cases assume a bad player from a very low k/d; regardless of game mode, if you're feeding the enemy vsats, you aren't helping.
Worst thing about grammar police: They're cannibals. If one makes a single typo or error while 'critiquing' someone, they will be EVISCERATED by their fellows.