Yes clamps can be too tight but not for the reasons stated above.
TL;DR The fear is that over-clamping will lead to a starved joint is largely baseless. In practice it is nearly impossible to do without severely damaging the wood.
Necessary clamp pressure has been studied extensively by scientists for the timber industry, who, unlike woodworkers, can't rely on hearsay, half-truths and best guesses. They have to know how to create the strongest possible joint. And such testing has proven that very high clamp pressures are required for the strongest joint to form, beyond 1,000 pounds per square inch for some species (NOTE: this is at the glue-line, so the pressure applied by the clamp face is many thousands of pounds)
For the home woodworker here's the take-home message: short of crushing the timber it's nearly impossible to over-clamp.
The persistent myth that you can starve a joint by over-clamping it is based on a flawed understanding of how glue works in a wood joint and/or misinterpreting individual experiences where this appeared to happen. The actual cause however was one, or a combination of, other factors. These include:
- too little glue applied, which leads to incomplete wetting of the opposite face
- waiting too long before bringing the workpieces together, which also leads to incomplete wetting of the opposite face
- not glueing freshly-worked wood surfaces — wood surfaces cut, planed or sanded can 'glaze' over time, meaning they're no longer as absorbent and therefore they can't be wet properly by the glue
- wood surfaces not flat or smooth enough, wood must be very smooth for a good joint to form with the mating surface
- clamps being removed before the glue had dried sufficiently
Note: the above apply to conventional wood glues, including polyurethane adhesive, but not to epoxy.
Lastly let me clearly state that Matthias Wandel's glue test linked to above is highly flawed and not at all scientific. He acknowledges himself that he didn't give epoxy a fair test (which he didn't) and yet he did not repeat those tests. That's the first hint that you might want to take the results with a pinch of salt.