Why do website registration systems suck so much

Ever notice what a pain it is to register on a website. Enter your name, username, password, age and some barely readable code. Invariably, at least half the time the registration bombs out for some not readily apparent reason. I particularly despise sites that won't let me pick my own password, instead insisting on some other or longer choice. I try to pick passwords I can remember. If I can't remember how to log in, the site becomes useless. Is it just me or does this whole system really stink?

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