I use it as a general guideline and something to fall back on. When I DM I don't really care what my player's PC's alignments are, it's just one descriptor of many. I don't allow evil PCs, but that doesn't really have anything to do with alignment. On the other hand it's a quick guide for NPCs and monsters that I can grok at a moment for their 15 minutes of screen time, especially when I wasn't expecting anything other than a brief interaction. It's a starting point of their moral compass.
For my own PCs sometimes I think about it sometimes I don't. If I had a DM that told me I had to play a specific way because of my alignment, I'd find a different DM. The tail doesn't wag the dog.
For my own PCs sometimes I think about it sometimes I don't. If I had a DM that told me I had to play a specific way because of my alignment, I'd find a different DM. The tail doesn't wag the dog.