Recently, many of my friends have been switching from LoL to Dota 2. why?
The games themselves are quite similar. Dota 2, only differing in that it can allow for more aggressive gameplay, since you can have an activatable building fortication buff every 5 minutes (not strictly confined to lanes), the ability to deny ones own creeps, and the lack of summoner spells.

Can anyone tell me why my friends might like Dota 2 over LoL? Do the aforementioned items change enjoyment of a game THAT much?