Is channel enablement mainly a sales function?

It would be if all you wanted a channel partner to do was sell your products. Without marketing that would be, at best, difficult. Your own marketing is broad-brush and your partner needs dedicated messaging. Lack of executive buy-in from the top can often be crippling to any endeavor, so you want to enable them to understand the benefits of selling your products to their business. Your partners may be fine with paying someone else to install and otherwise service your products, but they’re giving away a large chunk of their most profitable opportunity. Without that, not many partners will want to stay partners for long. The answer to the question, in short, is no.