Which is particularly relevant at consultancies where the product is a service.
If you join a consultancy group, and 2 months later quit with the client roster... is it really OK to poach all their clients to start your own consultancy?
All of these contracts are time limited, FWIW. E.g. non-solicitation doesn't mean you can never work your your colleagues again. It protects against someone leaving and then immediately poaching all employees within 12 months. After 12 months you're welcome to poach as much as you'd like.
Edit: Furthermore, non-solicits don't ban your colleagues from quitting with you, as long as you're not directly asking them to quit. If they make the decision independently without being lobbied by a former employee, it's not in violation of non-solicit.
If your company didn't pay you enough to keep you, nor did provide good environment ans support? absolutely yes.