Not saying he can't, but one consideration for him is that the business model is different with ci-en and patreon (I'm assuming subscribestar is similar to patreon).
With ci-en, it's less of a subscription and more of a monthly payment for that month's "product". Meaning, when you "subscribe" to Inui on ci-en, you only get that month's paid content. If you want previous content, you have to "buy" each month individually.
Patreon works more as a normal subscription where if you subscribe, you get all the paid content as long as you're willing to scroll.
This matters less with game updates since it's always going to contain previous content, but I can see why it might be discouraging with his non-game content. If I can subscribe and get all of the paid out-of-game content rather than having to "buy" each of them individually on ci-en, I'd be more likely to subscribe even if the subscription rate is slightly higher than ci-en's rate. Although he can always math out a good and fair rate for the patreon model, he might think it's too much of a headache/hassle (given his struggles already) to properly set one up.
