I'll recline slowly, but I paid for a seat that has the ability to recline, and I likely intend to use it. It's not selfish to expect to use all the functions of the seat, and I expect the person in front of me to do the same.
If one has physical needs that make it impossible for the seat in front of them to recline, they should request bulkhead or other seats with extended space.
With regard to the fast recline, some seats take more effort to recline than others. Is it possible when the person in front hit the recline button, the seat had no resistance and simply reclined more quickly than expected? I've had that happen, as well as seats with more resistance than expected which required a hard push to get to recline. Sometimes resulting in a snap recline in the end as well.