I call bovine excrement on what 'that guy' claims.
To answer your question: yes.
The GTX 750 ti is one of the most power efficient graphics cards available and there are models which do not require additional power connectors for them to work; they can run using the power supplied by the PCI-E slot and were designed to do so. Some models may have more elaborate cooling which may require additional power, but not all do.
I personally have an
MSI GTX 750 ti 2GB Gaming which does not require a power connector even though it has two fans.