[nip]

Following that user in "web development" instead of "everything" (a la twitter) will solve his issue. You follow people within categories, you don't associate people with categories.

I probably didn't phrase it correctly, I stand corrected.

When you share or save something on tree, you have to choose one of the 20 categories: tech, business, news&society, art&design, music, etc... In turn, people will see that you shared in X or Y and can decide to follow you exclusively in this X or Y category. Your feed is actually a multi-feed (depending on how many categories you decided to follow people in, up to 20).