I will be blunt, and tell you that your expectations are totally unrealistic, for many reasons. First and foremost, Memrise “courses” aren’t actually courses in the academic sense, but rather sets of flash cards containing fact pair sets. Hours of studying flashcards are not the same as “hours of instruction” such as would occur in a school or private tutoring setting. There is a reason why courses in school are structured as they are, with integrated lectures, readings, practice, review and testing. You don’t see universities handing their students flash card sets at the beginning of the school year and sending them on their way.
Learning doesn’t work that way. Pianists don’t develop proficiency from playing with flashcards, and neither do plumbers or electricians or engineers or doctors or lawyers. They develop proficiency by following a concentrated, and integrated program of professionally designed study and practice.
So if you were to play with the Japanese flashcards on Memrise for 365 hours over the course of a year, I would be very surprised if you would even be able to utter “a few butchered words of Japanese” at the end of the year.
Reliable studies of second-language acquisition of languages such as Japanese, show that it takes 700-1000 hours of intense full-time study and practice, for example in small private classes, to acquire a mid-intermediate level of proficiency, such that you would be able to engage in simple conversation, and do very simple concrete things like order a meal in a restaurant. But at that level, you would not have the ability to express or understand abstract subjects or engage in ordinary day to day conversation easily, and forget about functioning in business contexts. For example, with such a level of proficiency, nobody would hire you to work at their fruit and vegetable stand.