There are more and more people with thinking like yours in the thread, so you're definitely not alone. I also follow series with long waits, and the wait doesn't bother me. What bothers me is building up to a specific situation, having a long wait in between, and then having that build up be entirely pointless. Their meeting could have gotten postponed for better reasons, or maybe not set up at this point in time and instead set up later, and various other ways to go about this.
I understand, but I think it still served the purpose of showing what Mai is up to and how she feels, and she had to be aware of Asumi's presence for that to happen. Of course, the way the rug got pulled from under the readers is an old dumb cliché, but it's the kind of dumb I expect from this series since its entire premise is. I'm not holding it to a high standard for writing.
Also I'd personally prefer it if the series got past the meet up, and found a new goal to work towards afterwards. The author could have the series go for a couple of volumes even after they meet up, explore how all the characters interact together, expand on the main pair and if they actually get together or not, side pairs, and so fourth. The art is nice, I just think the author could handle expectations and pacing better. Especially with this frustrating turn of events.
I'd like that too but it's not usually how it goes in this kind of series so I'm not expecting it. It might have to take a bit of a weird turn to get there as well, the premise should be fulfilled once Asumi and Mai meet since Asumi started doing this brothel crawl specifically to find her. Either they start dating once they meet, in which case it would be strange for both of them to keep doing what they're currently doing, or they agree not to and Asumi still keeps hiring prostitutes because she likes it, but in both cases I'm not sure what new goal to work into it.