However, I've found on the couple of occasions where (non-reasonable) NCAs were presented to me that simply claiming that the terms as stated are not acceptable and that a revised NCA must be prepared if I am to sign it results in a shrug and a 'Whatever. We'll just skip it, then.'
Now, if they'd stood their ground, I'd have had to look elsewhere. (I am not a big fish - just a lowly engineer who do some management on the side - so they didn't waive the NCA for REALLY wanting me to come aboard; more from reluctance to go through all the hassles of either doing another hiring process OR amending the NCA.)
(At a former employer, the NCA basically stated that anything I ever thought of, be it at work or after work, in my field of expertise or in whatever unrelated field, belonged to them. Oh, and this obligation extended past the termination of employment for a period of time decided at their discretion. Not enforceable in the least, but still...)
If the candidate accepts the contract as it is the company wins.
If the bargains around clauses it's still OK and having many clauses to drop makes it look like the company is being flexible.
Always push back!
Just speak to your future line manager and explain that you have returned a modified version of the contract and that you hope that they will agree to it soon because you are really excited to start working.