What exactly is an RP tech responsible for? Evaluate a hazard (Radiation) and inform the worker. It's pretty simple, and not life threatening, at least in the normal work of a nuke plant. The union laborer actually does things that are life risking, and has to have a skillset (material handling - forklift, rigging, etc) that is harder than RP.
Sorry to burst your bubble - been in this industry almost 40 yrs. RP is not the lifesaver you believe it is.
Nobody ever said RPs were saving lives, but the simple fact is that we all have skill sets and a laborer's is not nearly as technical or challenging as a good RP (not all of them are worth their pay, but then again neither are all operators, electricians, managers, etc.) The legal implications of doing RP work are significantly more complex than a laborer, the knowledge required is much higher level and technical skills are more demanding as well. As long as things go well, nobody cares how well an RP does his or her job, but when the fecal matter impacts the rotating air mover either an operator or an RP is probably going to get blamed. If the operator is found at fault he gets more training. If a contract RP is found at fault he loses his job and likely his career. A house RP might get another chance, but probably only one.
As for a laborer doing things that are life risking... BS. Anywhere a laborer goes, an RP was there first (probably before the scaffold was deemed safe.) Any area a laborer works in, an RP is probably right there or was there. Any job a laborer does (rigging, by the way is not normally a laborer's job and RPs sometimes drive forklifts, too) is no more complex or dangerous than an RPs job or most other technical jobs. (BTW, if it was dangerous or life threatening, those of us that are intelligent enough to recognize that would do something about it.)
Everyone has their job. Laborers have no experience requirements and little required training above 'read this sign, pay attention to this siren, recognize this hazard, don't lose your badge.' ALL of the technical fields have more restrictive job requirements. Sorry if you are so blind that you can't see the value in that. Are all RPs worth more than all Laborers... not even close. But again, neither are all operators or managers... or executives.