Just my $0.02, as someone who's been building things on WordPress more or less full-time for something like a decade now, and working with various other CMSes for another decade before that.

> Cosmic JS is a drop-in replacement for WordPress

I don't know what "drop-in replacement" means in this context. To me, a drop-in replacement for WordPress would offer one or more of the following features:

1. Connect to my existing WordPress content database and use it as its content store

2. Use my existing WordPress theme to define its presentation

3. Provide APIs that are 100% identical to the existing WordPress APIs (the Plugin API, the REST API, etc.)

4. Allow loading and running existing WordPress plugins without modification

I don't see how Cosmic JS does any of these things. Some of them it addresses partially, an example being that there is a content importer available to pull content in from a WP site. But that still doesn't feel like a "drop-in" solution to me. A drop-in solution means I can pull out WordPress and replace it with the new thing without having to think much or rebuild anything, which does not seem to be the case here.

> We noticed that lots of development time was spent building and maintaining the CMS itself, sucking time away from core application development.

I don't understand this. WordPress famously installs in five minutes, and once that's done you only have to deal with it by installing updates, which is increasingly something it can do on its own without your intervention.

It may just be a matter of semantics - to me, "core application development" on WP is everything you do beyond installing WP itself: designing content architecture, selecting or building plugins and themes, etc. The "application" in the WP context is the complete bundle of database content, first-party code and third-party code you assemble to create a given site.

> automatic updates caused sites to crash

I have literally never seen this. Never. If anything, my complaint on automatic updates is that the WP core team has been so cautious to avoid breaking sites that it's made getting automatic updates into the hands of WP users a glacially slow process.

> a client would decide to install a bunch of plugins that caused the site to crash

Any sufficiently popular CMS that allows third-party extensions is going to have this problem. There are going to be third parties out there writing crappy code, and users out there who get dazzled by the marketing of that crappy code and install it. If your solution to this problem is to tell users they can't install third-party extensions, or to drastically limit what those extensions can do, you're going to be at a severe marketing disadvantage to systems that don't have those limitations. There are lots of dumb people out there who desperately want to do these dumb things, and don't like being told the reason they can't is because it's for their own good.

> comment spam was a never-ending battle

Turn comments off (which you'd do on any non-blog site you're building with WordPress), problem solved. If for some brain-damaged reason you want comments, install Akismet (https://akismet.com/), problem solved.

> We're the only headless CMS that comes with a community of developers built-in

WordPress itself is becoming a headless CMS. WordPress.com already provides a REST API (see https://developer.wordpress.com/docs/api/), so if you just want to host your frontend and let a remote service host the software and database, you can do that with WordPress. (You can also do it with self-hosted WP, but the value proposition is less obvious there since you still have to run and maintain all the complicated backend stuff.)

If what I really want is a headless CMS, and WordPress has already started providing me with a way to satisfy that desire and is clearly going to be doing even more along those lines in the future, why should I switch? What do I get by switching that compensates for losing all the other stuff that comes along with using WP?

> providing hundreds of apps, extensions, and integrations

I guarantee you do not have as many of any of these things as WordPress does.

Please note that none of these things are issues with the Cosmic JS product itself. (For all I know, it may be very good!) They are 100% about the way you are pitching and positioning it. If you came to me, a guy who's responsible for dozens of WP sites, and used this positioning to pitch Cosmic to me as a replacement engine for all those sites, I would not find it to be a very compelling pitch. A cursory examination of the product leads me to be skeptical that it would really be an actual drop-in replacement -- and if I'm going to have to rebuild those sites to use the product, then suddenly it's not just competing with WordPress, it's competing with WordPress and every other potential CMS I could rebuild them on. Now I'm doing what (IIRC) Joel Spolsky called "the dreaded market survey," which means now there's a million paths I could end up going down other than the one that leads me to buying your product. You do not want that. You want to keep me focused tightly on your product, not start me out window shopping.

So my suggestion would be to retune the way you pitch this product. If it really is a drop-in replacement for WP, make it clearer exactly how and why. If it really isn't, then don't pitch it that way. Find some angle that Cosmic JS has that both makes it superior to WordPress and is clearly taking it in a direction that WP can't or won't go, and lean on that.

I hope this advice is helpful, and that it is received in the spirit of cheerful willingness to help with which it is sent!