More on bad webservices

I am using postfix on my server and it has the nice feature that it can move mails with +something at the end into a folder I want. This allows me to see who is selling my email address to which company and such. Now the downside is that many forms of webapps claim that my email address is not valid.

So today I was over at finanzen.net to try to register a new account and instead of telling me that they do not like my valid email address, they say the user name was already taken. I tried with many usernames (coming from pwgen) and all the same, it just started to work when removing the '+' from the username...

Now I tried to use their contact form to tell them that I would like to use their service but they have hired a company that has no clue about web programming... well it is ofcourse broken too...

It is 2010, there are so many good web frameworks around, why are proprietary webapps still so bad? Who is writing all that crap?