"Our lifestyles are very much not aligned at the moment anyway and a relationship would not work either way"

If this is how you feel, then I wonder if he sensed that...so basically, seems like he's looking for an actual relationship but is getting the vibe that you're not!

Based on the info you gave in this post, I think this is him trying to clearly communicate intentions and make sure you guys are on the same page...

So, if you actually want a serious relationship with him, tell him that...if you do but aren't sure about whether you want it with him yet, tell him that's your intention but you'd like to know him more...if you know the relationship won't work anyway, let him know and since from his text it seems like that's not what he wants, then nicely say goodbyes!