I've had quite a few customers break rocker arms.......before they were my customer. It comes down to application, and installation.
If a Proform rocker is used on a solid roller, you can bet it will have a short life. If the rocker is correct for the application, but isn't set up properly i.e. fitment and geometry, it too will have a shortened life span.
You have to ask yourself, "what do I intend to do the engine, and what rocker will be durable enough to live in that environment, all while fitting the build budget". Everyone has a budget, and to throw extra money at parts that are overkill or unnecessary, is just a waste of hard earned dollars. If someone wants to sleep better by buying expensive parts when not necessary, that is certainly their perogative, but it does add to the cost without any gain in performance, and many times no added durability.
For builds that need a top notch rocker, I have T&D make rockers to my spec. That is the only way to get good rocker geometry, because none of the "off the shelf" rockers are correct, regardless of the brand or country of origin. They can be helped, and acceptable for moderate builds, but will always be a compromise when it comes to geometry.