Welcome to APUG! Hope you will stick around.

I shoot with Pentax 35mm, Leica 35mm, Hasselblad 6x6, and 5x7. So there's a big variety to what I do.
Honestly, square or rectangular, I just usually print the pictures the way it feels right to print them. Sometimes I crop square negs to become rectangular, and vice versa, but it's always the content of the picture that dictates what I do, and with our prints we must support the content to the very best of our ability. Cropping can be a very powerful tool for this.

Having used Instagram a fair bit for about a year, I got tired of everything being square, and even found an app called Squaready, which allowed me to fill out above and below horizontal shots, and to each side of vertical ones, with black or white, or any other color, to make it square, so that the Instagram uploader wouldn't automatically crop them for me.

To each their own. But I agree that anything that has the power to inspire new photographers is a good thing. I'm glad you found something to inspire you!