I don't follow much Dota 2 competitive play, but it just feels like Chen isn't being used nearly as well as he should. I feel like he should be much aggressive while jungling. Maybe the creeps just aren't as strong in Dota as HoN, because Ophelia is pretty much the best jungler.
Were you the same guy that asked this question few weeks ago?
Long story short, Dota 2 and HoN are very different games today. The balance and meta are sensitive.
Even a year to year and half ago, Dota 2 didn't have all the heroes released. Riki was top pick against AM's blinking. And 18 min rax pushing meta was very strong due to anti-push heroes not existing then (Keeper, Gyro, Treant's heal, etc didn't exist).
Ophelia being strong in HoN has little to do with Dota 2's Chen. It's certainly not lack of skill (come now). I'm not familiar with today's HoN, but I'm sure they departed a lot from Dota with their own items, heroes, and spells.
Oh, Dota 2 got numerous and numerous buffs to EXP gain, assist gold, introducing reliable gold, kill bounty gold, and kill gold. All this to make the game much faster paced. This makes Chen not as oppressive as HoN's counterpart.
Weaker heroes = static creeps are more oppressive and stay relevant longer.
I bet that's one of the primary reasons.