Maybe you were strongly affected by A Streetcar Named Desire, and you have to defend Stella no matter what, but your devotion to a brand which is not your first choice is kind of weird.
It's not a devotion to Stella, it's an opposition to beer snobs.
So what's actually wrong with Stella? 'It's like Miller but more expensive' isn't even a defensible argument unless you quite literally have no tongue to taste the obvious differences. Hell, I don't even think I need a tongue to taste the difference. Stella is better in every way.
Your comparison to Pilsner Urquell (a beer similarly priced but distinctly different) doesn't make much sense at all. The negligible difference in price you cite (by the way, Stella's cheaper around here) still doesn't mean Stella is somehow 'worse'. It's different enough from Stella for me to be able to enjoy both separately. My go-to pilsner as I mentioned before is Tyskie, which I think is different enough from the other two (heavier than Pilsner Urquell and more bitter than Stella) to stock alongside both.
I also prefer Basil Hayden's to Evan Williams but I stock both. I like Glenmorangie but still have Laphroaig.
Calling Stella crap because it isn't a Trappist ale or heavy stout (which seems common among Murikin beer snobs) is a projective expression of virility and not a statement of taste.