There are two major trends at work behind this idea: the first is that its safe to say that the Balinese have more ceremonies than perhaps 90% of other cultures — and parading and wearing special clothing is part of their rituals.
Secondly, both the Balinese and a very large number of visitors get married in Bali. And while we know what Western bridal clothing looks like, the Balinese kind-a own the wedding look:
I mean, wow!
Participating in Mardi Gras is done with considerable flare and, if you are a true contributor, some form of elaborate costume will be required. For the Balinese, the embrace of extravagant color, attention to detail, and over-the-top decorations are true artistic achievements as well as major status statements.
If you are visiting Bali and attend a dance/music production on the island, or if you stay for longer than a week, you will most likely see well-adorned Balinese entering or exiting their temples.
And to be fair, both the Balinese and the Mardi Gras contributors do their darndest to turn it up to 11: