> one cannot sign a contract electronically

This obviously varies by jurisdiction, but if you're US based you can absolutely sign electronically (there's an entire Act that enables it). The easiest way is to use services like Echosign or Docusign which most people are pretty familiar with these days.

I wouldn't want to work for a client who chooses freelancers by how easily they can be exploited. Having a perfectly reasonable contract is no reason for an ethically run business to not work with you.

While there can be legitimate reasons to not move forward based on some contract terms, either way if there is a deal breaker that probably isn't a great fit anyway.

I sent those types on to try other contractors. Not worth it for me to repeat my own [unpaid] history.

People can sign contracts electronically.

Why not? I e-signed mortgage paperwork.