Ask HN: Are technical founders typically treated this way?

Recently, a founder from a former company I worked at reached out to me regarding joining their new AI-venture. They approached me because I had experience as a founding engineer of their previous company (in the same space, but several years ago pre-AI hype).

We discussed the problem space, my experience in it, advances since the last venture, etc. They showed me a very rough prototype (something anyone could do in a day or two using a few public APIs).

They offered 5% to 10% in equity (remaining equity split between the would be ceo and co-ceo). I proposed an equal split across the board and I proposed an option to draw a fair market salary post funding without giving up equity to do so (we would be doing this for ~8 months with no salary).

My reasoning was simple enough. I wanted enough equity to make it through seed and series A/B/C. I also wanted the salary post funding to offset some opportunity cost, etc. I also made it clear, although they made a rough prototype, the vast majority of the work is still ahead and given the technical nature of the product there will be a lot of it.

Needless to say, they didn't take it too well. Although we ended things friendly, I could tell they were not very happy with how it ended.

Am I the unreasonable ass here?

I left feeling like the technical founder role was a glorified code monkey. Why give the technical founder more than 5-10% when you can pay someone offshore to "do it"? This of course, ignores all of the work I've done in the problem space. The experience I have working with one of them and so on... I'm not sure what the best way to describe how I felt was... undervalued? devalued? Engineering is a commodity? Honestly, it made me question if I wanted to build anything anymore at all.