Why subscribe? because it's hard for me to communicate to you. Some social networks die and then I lose my connection with you. Some (mostly all now) social networks force paid-for posts simply for me to be able to talk to you. Lastly some networks change the rules of engagement and gimp the communication tools causing various levels of censorship.
Having your email is my best bet at communicating with you again in the future. I don't send out much, in fact I should probably communicate more. The point is, it's my way of being able to say 'Hi' every now and then without being controlled by some higher power (minus overzealous spam filters).
if my email ends up in your spam, please add me to your safelist.