I think its important to remember the context of where this game was made. The views of sex and sexuality in Japan are extremely different from how we view them in the West. Host and hostess clubs, maid cafes, soaplands, every crazy sex toy imaginable, there's a whole range of services dedicated to various aspects of "relationship replacement". Summer Lesson may seem strange and somewhat creepy from a Western / European perspective, but in Japan it honestly is pretty tame and fits right into the host/hostess club and maid cafe scene. Why go to a club and pay a girl to talk to you and pretend to be interested in you and cuddle with you when you can get a similar service in VR? Its not like experiences at a hostess club or a maid cafe are any more "real" or any less objectifying. In America (and I'm assuming other western / European cultures) there isn't anything in the real world that correlates with the experience, but it really does seem like a more involved VR version of a maid cafe or hostess club, where the experience isn't supposed to be explicitly sexual per-se, but more supposed to invoke feelings that a lot of Japanese people, especially men, are struggling to find these days, such as just having a simple conversation with a girl that they are attracted to who seems to care about them. If there's some fan service in there, some suggestive behavior that's never truly acted upon, some flirting, then even better.
TL

R; somewhat normal in Japan, creepy in America and I assume most other western cultures.