My apologies Mokona; when I first answered your question, I joined MDL not too long before, so I didn't really get hit with the MDL craze yet :D ;)
Now I feel like I get the feeling that you are talking about. I don't know if that's pressure necessarily or just pure curiosity that is sparked by people on MDL, but the more I come here, the more things I want to see. Once I get into my head that I want to see something, I keep thinking about all the other things I wanted to see... That creates sort of a feeling that could be described as being pressured. I think I used to savor dramas more before joining MDL. I would look for the one particular drama I wanted to watch for days and then slowly decide on it. There weren't 20 other titles that I needed to see ASAP ;) Now I have 45 items on my PTW list and it's only because I keep myself from adding about 30 more I think I might be interested in :D
So yes, all in all, there seems to be internal pressure that being active on MDL can create ;) Thanks to MDL, I definitely found a lot of dramas that are gems, but I also watched at least 50% more dramas that I would otherwise. Also, I finished about 90 dramas.... that is a TON of dramas and time invested in one hobby for an average person, but nothing impressive on MDL ;)