It's said "you won't get fired if you use proven standard".
Standards are important for they instill trust in customers.
It's easy to view a webpage and just check if there's 'Lock Icon' or https:// word in the page's address.
If not, is page secure? Perhaps yes... perhaps there is 'custom encryption method', but i would not trust it to instill security in customers.
Standards provide for many ways of increasing security. When we know what we are provided, we can work with such tools and enhance them.
On the other hand: is page encrypted with standarized methods totally secure? No, but still more yes than no... for it's hard to break. Given enough of time and means, any page can be hacked (for example: see 'birthday attack' in this post).