Well, I agree with that ... but with qualifications.
Spring clamps certainly can provide enough force to clamp up a top, IF you are using enough of them, and the right sizes, and correctly distributed, etc.
C-clamps do provide much more force, and force you can adjust. As mentioned (and for really any clamp) you need to use clamping blocks to spread out the force and not damage your good surface.
There are a lot of different kinds of clamps and ways to clamp things. No one type of clamp will work for everything. Also, there are lots of different clamps that will work for a given job. You just have to choose something that is appropriate to the task at hand -- and available to you.
I almost never use C-clamps these days (and then usually only for metalworking), because I have a lot of other options that all are better or more convenient. But if you don't have a lot of gear, the C-clamps will be infinitely more versatile and useful than the spring clamps.
Just keep in mind that more clamping force is not always a good thing. If you clamp so hard that you force all of the glue out of the joint, it will just fail later. You need to clamp enough to get a little glue squeezeout (to ensure good contact) and leave it alone. If your parts don't fit well together, you need to correct your parts, not try to make up for it with bigger clamps.
No matter how many clamps you own, there are always more you need ... because as sure as death and taxes, you can never have enough clamps.