Is it harmful to turn your computer off using the glowing blue on/off button on the front of the CPU?

In the 90’s our IT guy told us that doing that will eventually wreck your hard drive. He said I needed to use the controls and let it shut down in its own time. However, the other day my husband said he talked to a local tech (which we seem to have a plethora of now) who said it won’t hurt it.

Which is true? Or have the systems changed so much that it used to hurt it but now it doesn’t?