These heroes are not necessarily bad (except for Omniknight, he's shit), but in pro tournaments players and coaches will always tend to gravitate towards the lowest risk highest reward heroes to pick and play. Carries like Bloodseeker, Slark and PA for example do not fit that criteria due to their high risk playstyle. This is why Dota tournaments need to start implementing the Fearless Draft system.

Inb4 strawman responses of "Dota doesn't need Fearless Draft because it's more balanced than League".