check the node count. it's been slowly falling away. it's blockchain size, bandwidth, downloading. hassle. there ain't many committed enough. huge blocks will take out many of the people who want to keep going but it won't be practical for them.
Block Size (kB) 1 hour ago like 11.20 (kB) that's not the issue. Seemingly there aren't so many eager beavers lining up to get their dumps through to the exchanges, the blocks aint overcrowded.
The real handicap is about having to maintain two chains, and keeping them up to sync. Maintaining wallets.
That's the real reason for centralized exchanges, people storing their altcoins over there as a service.