Re: because we need all phones to be equal.
Ramps aren't about preventing discrimination, but allowing access.
People don't start off with "I don't want to hire people in wheelchairs how can I avoid that" and end up with "I know I'll make sure there are stairs everywhere".
People who don't want to hire disabled people have a problem in their head they just wont hire them, they might well still put ramps in and still just not hire them.
The way to prevent discrimination is through recruitment processes that ensure no one person makes the decision and those that do must independently justify their personal decisions before the final decision.
A good starting point is Joel's approach: http://www.joelonsoftware.com/articles/GuerrillaInterviewing3.html
Obviously this stuff varies on the size of the organisation a one man band cannot have multiple interviewers for instance.