I know that there are reasons to have rentable bicycles around Boston. It's a great concept! People should be encouraged to bike around the city instead of use cars. I also know that you talk about the importance of safety while bicycling, including providing more affordable helmets. Safety is important, and certainly overlooked by too many.
However, the bikes you provide are absolutely in no way safe.
It is not safe to cause people seizures for doing something as simple as walking down a street where someone has chosen a to ride. Your bicycles do such things. Flashing lights, your flickering lights, cause risk of death for many with photosensitive epilepsy.
It is not safe for people like me who don't have epilepsy, but have other photosensitive disabilities. If my brain stops being able to process things properly because of the flashing lights of people riding your bikes by me, I might not know where I am, what I'm doing, how to walk. It is not safe to be trapped, because you have decided that flashing lights are what to provide.
It is not safe for those riding these bikes either, as studies have shown that drivers struggle with identifying distances when the lights are flashing. Solid lights are much less disorienting even for those without disabilities. Solid lights people are capable of recognizing what they're seeing.
But even if it were fine for the riders, even if it were safer for them, it is necessary that people with disorders such as epilepsy be capable of doing things like grocery shopping. It is necessary that you take them into account for your business model, instead of doing things which are easily fixed, and known to be problems for the most famous trigger for a well known disability.
It's not reasonable to ask someone with epilepsy to not leave their house, because they might meet a flashing light if they exit. The fact that this is the approach many people take does not make it acceptable.
It'd be a lot safer, more straightforward, and more reasonable to simply have you make a small alteration. Swapping your bicycles to use safer lights, non-flashing ones, would make things safer for everyone.
Lights which let people see, know where each other are, and those of us who are walking, be capable of having our brains not backfire into whatever our disability has been triggered into today. Lights which let us be members of the community, rather than prevent us from taking part. Lights which don't cause people to know, that leaving their home is a roll of the die of what they're risking today.
Please, make the changes to make your bicycles safer. What you have isn't safe. A small change can make a big difference.