Few reasons:
1. BCH is a fork by developers who are more aligned withe certain mining companies. The prominent faces for BCH are Roger Ver, Jihan Wu, and Deadal Nix. Most of them do not have good reputation in the crpytoverse.
2. Jihan Wu, and his company - Bitmain, has bad reputation for exploiting miners for profit, and disrupting mining ecosystem. 
3. Most people cannot accept the fact that cryptocurrencies have a "CEO", a.k.a. Roger Ver.
4. BCH has less full nodes than BTC, hence arguably less secure.
5. BCH is more centralized in the sense hard/soft forks are decided without polling community. Where as BTC forks are usually carried out after polling done for BIPs.
6. BTC is maintained by the existing BTC developers for years.