Being a good guy probably ranks the least IMO for leading VC. You need to be extremely shrewd and calculative, have a great bullshit detector, need to have solid intuition based on scant data, good general knowledge, well versed in various industries and areas of study, pragmatic and brutally honest. I am probably missing a few more. Speaking generally, nothing against Garry.
>>system+(OP)
Do both. There's nothing preventing you from looking at the numbers, the pitch, and saying "no." In terms of being "good". You can be honest and kind the same as how one can be honest and mean.