What part and no double talk.
You said it's prohibited to turn a light on, so the shabulb is a loophole. That's incorrect. The Torah does not prohibit turning a light on, there was no electricity when the Torah was written.
The prohibition stems from igniting a flame. It's a very technical question: does this constitute igniting a flame? Since it clearly doesn't, it's not prohibited.
Moreover, what I think you don't get is that we follow the letter of the law only, not the spirit of the law, unless the letter of the law expressly requires us to take into account the spirit of the law (such as with zilzul Shabbos).