How can you want a relationship but not think about the future of it?

Anonymous
My current partner heavily pursued me and early on said his intention was dating with the intention of marriage. I believed that on the grounds that he's only been in a few serious ltrs and was going to propose to the last one, but she left him abruptly.
I ask him questions about his mindset a lot on different things, but he is sort of old fashioned in avoiding too many emotional topics, etc.
He constantly says he loves me, but he can be very non-affecfionate/non-complimentary.
Fearing it was a case of losing feelings/not taking me seriously. I gave him an out and essentially said something along the lines of "If I'm not what you're looking for, just let me know, and I'll go because I want the real thing a husband and a family etc.
He retorted that I was wrong, he loves me and he wants those things too. So I conceded, and things went back to how they have been. He acted a little more attentive for a short time right after, but now we're back to the seemingly platonic relationship mode.
I calmly asked him the other day what he thinks about us and about the future and he said he doesn't really think about that stuff (what?) And I brought up that he had talked about marriage previously when he planned to propose to his ex and he said that he didn't really think about it until the last 6 months of their 3 yr relationship.
How can someone never think about that sort of thing if they're in a relationship with someone that they're "dating with the intention of marraige" like I understand waiting, we have only been together a year but how does the thought never come to mind?
Surely, if he decided that he didn't want that with me, he would have taken the out, right? I'm just trying to understand not thinking about a future in a serious relationship.
How can you want a relationship but not think about the future of it?
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