The boss was discussing with his secretary about the applicants for some job vacancies in his organisation. His secretary paraphrased two sentences from an applicant's covering letter. In reported speech, his secretary said: "His (referring to the job applicant in question) only interest is to gain experience that would benefit a private law practice. And he has no interest in being here (referring to the organisation to which he is applying for a job) for any period of time which would render employment speculative."
Thank you for providing that context and explanation (post #3); it's really helpful. This is apparently a large law firm. The secretary is saying that (in the secretary's opinion), the person applying for the job just wants a bit of experience that would be valuable for going into business for himself (that is, opening his own private law practice); he has little interest in a career with this large firm and very likely wouldn't be staying very long. In the secretary's opinion, employment of this applicant would therefore be speculative (something of a gamble)—because if he's probably going to leave in a short time, it's not worthwhile for the firm to invest in training him, involving him in the firm's activities, etc.
Would it make sense if the applicant himself states so in his covering letter? Suppose I am the job applicant and could I write "I have no interest in your company for any period of time which would render employment speculative" in my covering letter?
As Myridon says, no job applicant would apply for a job saying, in essence, "I'm not going to stay at your firm very long; you'd really be training me to leave your firm soon and open my own business." Of course no company knowing that would hire the person. Would YOU?