Not really "stupid" in general, but for me personally... working in a program that had no text tool rip me :c Even worse when my workflow is kinda erratic, not just the usual "draw ALL the sketches before you draw ALL the outlines before you draw ALL the colors" but instead I might have outlined panel 1 and 2, while 3 is fully colored and shaded and 4 is still just a sketch, and currently I'm working on the background of panel 5 where only one of the 2 character is drawn yet. So for me it's not just as simple as "write in all the comic text at the very end" (also because I need to make sure the text actually fits, even when sketching bubbles it can be hard to know before actually writing in the text. What I did was opening the image in GIMP, adding text and then saving just the text as a rasterized layer... which would be a pain if I ever needed to correct a typo) SAI is a great art program by all means, but for comics... they've been so much less stressful to work on after switching to Manga Studio. I'm kinda amazed by all of you who can comfortably work with multiple programs for one image, haha... with my workflow I'd just keep switching back and forth.
Also, working at 900px for a long time instead of working big and resizing down. Not because I want to print but because I had to work so "small" (which sometimes made me size up characters/other objects unneccesarily so they wouldn't be annoying to draw). Then I saw threads with almost everyone saying they worked on a much bigger size and sized it down afterwards, and even though I thought at first "nah, that's not neccesary, my art is fine the way it is" I couldn't help wondering if there WAS something to it... so I started working on 3000-2500px wide and then sizing down... and somehow it actually looked better? (Plus sometimes it hides tiny mistakes better hehehe)