Point #2 is technically correct, but I think it's perfectly legitimate to block people from recruiting your employees at your place of business, while they are working.

Lyft isn't trying to block Uber from contacting Lyft drivers at home, on Facebook, on LinkedIn, etc. They are trying to block them from abusing the Lyft service to recruit. It would be like Apple trying to block Google from waltzing into their HQ and walking from desk to desk trying to recruit their employees.