This happens so often in JAV I don't understand it sometimes. Why have girls like Hana Kano and Miki Sunohara doing lesbian, handjob movies etc when clearly they are blowjob queens! It would be like signing Messi to your football team, and then asking him to play in goal!
Maybe some people like the variety of scenes, or maybe it's because they have to pay them more to do it, but I personally would not mind if girls like this released one blowjob only video a month. I don't think I would get bored!
Another case in point from the post above, Hina Nanase is a good deepthroater, in this movie she spends most of the time smiling while giving handjobs... What a waste of talent!
It is the same for Gokkun, take Akari Mitani for example.. early in her career she released a few movies with Gokkun, and she deals with semen like a champ! Yet since then, she doesn't swallow anymore. Such a waste!