That argument could be made but would have no proof to support that theory.
Agreed .... the debate has been going on since Arnold's day and will likely continue for years to come, in the absence of real scientific proof one way or another. I suppose the proponents of "the pump" are as individual as the misc compounds out there that claim to increase the pump .... for some it works for others it doesn't .... for some the pump is everything and for some its not all that important. IMO everything counts in the gym .... if you focus 100% on only one aspect of bodybuilding then you will fall short every time .... so with that being said, if the pump works for you and keeps you motivated to keep increasing volume and intensity and fills you with positive vibs then in that aspect its a good thing ..... whatever keeps you coming back and giving it your all in the gym.
As far as the pump having an anabolic effect, this is still open to much debate and probably will be forever, however many bodybuilders will claim with complete faith that there is something to it. When you get a good pump, you are delivering tons of nutrient-rich blood to the muscles that will greatly increase amino-acid uptake......Theoretically, this should result in a greater anabolic effect. Again this is not hard science but if it works for you then so be it. There is also the belief that a good pump can have a fascial stretching effect which will lead to more size gains.....again the scientific proof in this area is lacking but if it works for you then its all good.
So while the debate rages on regarding the importance of 'the pump' and the scientific data is not there to support it one way or another, there is probably something to gain from it regardless. All that being said, and as I already mentioned above ..... I would not make 'the pump' the sole focus of your workout.
As for me .... I get a positive feeling from the pump and that positive feedback goes a long way toward my determination and dedication to my goals in the gym. And we all know the power of positive energy