A thing I see becoming a problem are things disallowed in games like Street Fighter or UMvC3. It's becoming more apparent due to there being things you cannot use in the information section of a tournament. Although it's seperate from PvP, it's regulating it and labeling some things as frowned upon, cheap, or bad.
Another thing is it becoming an ultra-competetive game due to Dark Souls' cult following of very skilled duelists. While this isn't bad, it makes the game more of a chore than anything. There are games like Street Fighter where most people are very skilled and play to win, but it's still enjoyable, but it's because it is meant to be a competetive tournament fighter.
The last thing that concerns me is slowing the growth of Souls' games in general. If you look up "dark souls PvP" on Youtube, a majority of the videos are against gankers in PvP designated areas, or set-up duels in the like. Rarely do I see what PvP was meant to be, a tense cat and mouse game in the unique terrains and designs of Dark Souls. I'm so sick of seeing the Burg courtyard, Oolacile entrance, and the Forest. So personally, if I do even invade anymore, it's at a mid SL in an unconventional area for PvP. Bringing me to why this is harmful, in the fact it could frighten newcomers to the series. From what they've seen in videos, a good 80% of PvP is invading a PvP hotspot and fighting two or three overleveled people. Sadly, this is the case nowadays for PvP, and naturally, people want to win. So if you're a newcomer to Souls, would you take risk invading and get ganked, or get easy kills with a buddy in the forest?
While tournaments are fun and challenging, I feel having an oversaturation of set-up PvP is harming Dark Souls. Just my opinion on the matter.
No offense to people who host/participate in FC's and tournaments.