If I am not wrong, many people in Singapore also take more than an hour from their HDB to office each way using public transport. Crossing borders does have its hassles but it's a trade off that just have to be accepted. If cannot accept then should not move over.
Use common sense. There will be many who take less time to go to work if it is within Singapore. By MRT, I take 28 mins only from the time I step out of my home till I reach the door of my office. Travel time is less than 15 mins. There will be fewer cases whereby it will take more than 1 hour to reach work.
I am only pointing out why HSR and RTS may not change the situation of getting more Singaporeans to live in Johor and work in Singapore.