Raskhi is the is celebrated differently in these days. Previously around 40 -50 years back, it was totally a different type of celebration. No one was so excited about rakhi day. Brahmins used to come home and put color threads. They did not have clear explanation to what was the purpose of them coming and puting rakhi to all people. Some had some understanding of the purpose.
Recently The celebration has become different, turning the real purpose of raksha bandan.
Rakhi used to be for keeping promise. Keeping sankalp, strong decission for keeping yourself "Pure". Pure means keeping self clean. Clean has broad meaning of clean body, thinking, wealth. Raksha means "protection". Protect yourself from becoming the opposite of clean.
"I promise, i will keep myself Pure. Protect myself from becoming opposite of purity/cleanness.