If you're a professional and don't test Safari, you're not being professional. Don't have a Mac? Use https://www.browserstack.com or similar. Don't want to bother? Then, yeah, you're lazy.
I don't have a Windows machine. I still test against Edge. No Android phone. Still test against a range of them. How? See above.
"Therefore, for me to test on Safari, I either have to... pay out of my pocket for some sort of cross-browser testing tool (even if it's free, I am spending extra time)"
That's precisely the 'lazy web developer' that they're talking about. Oh god no, you have to test on a browser you don't use.
Sure Chrome is dominant, but Safari has about 15% of the market so by taking the stance you do, you're dismissing 1 of 6 people. Because you're lazy.
I don't have a Windows machine. I still test against Edge. No Android phone. Still test against a range of them. How? See above.