Out of curiosity, why do you tend to reply to recruiting emails when they demonstrate some knowledge of who you are? Although most recruiters don't do that, it's still fairly well-known (at least around here) that recruiters should do that at the bare minimum. So it seems to me that a mention of some fact about my life or work just means their recruiting team is more well-managed or -staffed. Maybe they tell their recruiters to spend 5 minutes on each person looking for a GitHub or Twitter account. Unless there's a positive correlation between the quality of a recruiting team and the desirability of the job being offered (which I doubt), I don't see why you would reply to these sorts of recruiting emails.