Even if bcash is better, look at IPv4 and IPv6. IPv6 is objectively the better standard. It has enough IP addresses that you could have one for every electronic device in your home.
IPv6 has been around since the late 90s. And yet we still use IPv4. Why? Everything has been built on IPv4. It's established. Getting everyone on the Internet to migrate to IPv6 just never happened. Could it? Should it? Maybe. But it didn't.
With limited IP addresses the Internet stopped working right? No. They just adapted and used various layers to represent the various devices you use every day. You may have one router in your home which then assigns a local IP to your computers and phones. Most people have dynamic IP addresses so that when someone's no longer using an IP address it doesn't just sit there, it can be used by someone else. The Internet adapted. The end of the world did not happen as the IPv6 advocates proclaimed would happen once we ran out of IP addresses.
So work with the current Bitcoin protocol and do what you can to make that work because that's what we've got.
IPv6 is used for some LANs and other things within businesses. Maybe bcash can go that route. Who knows.
I can tell you why IPV6 was not adopted out of the box and that is because there there baked in vulnerabilities that M$ and 3 letter agencies tried to push to us and we spent a lot of time and effort vetting that and stripping it out. As far as it's current iteration, I have no clue.
Yes, there was something in the encryption (I'm still not certain that the encryption was broken or it worked so well that the NSA didn't want people to use it). I recall in the late 90s getting a memo sent out to all government agencies warning us not to use IPv6, stating that the NSA found some vulnerabilities. Perhaps they found that they can't spy on each transmission.
But the key being the analogy of more IP addresses. A 1 or 2 minute explanation promoting IPv6 and bcash can easily convince many people that it is superior.
"We're running out of IP addresses/transactions per second. When we run out, IPv4/Bitcoin won't work anymore. This new protocol will fix that problem. Adopt it if you want to keep using the Internet/Bitcoin."
The fact that the supposed solution is broken does not make the sales pitch.