Received comments from reviewers with major revision. Is it worth pursuing?
As the comments point out, this is up to the editor. Nothing gets published without the editor's consent, and nothing gets rejected without the editor's approval either. Reviewers can say X, but it's ultimately just a recommendation that the editor can ignore.

In your case the editor said "If you are prepared to undertake the work required, I would be pleased to reconsider my decision." I recognize this phrase because it's the default one given by Editorial Manager every time the editor makes a decision (editors can edit the default email of course, but often don't). In other words, the editor for whatever reason has not expressed an opinion. This means there's still every chance your paper is accepted, and you might as well make the case for acceptance by revising it. 

That said, you should address why the first reviewer's comments are not applicable. Give your reasons why the experiments can't be performed ("cannot be carried out at this stage" is not convincing). Based on your description I'd certainly stress that you are modelling an experimental process and you've already compared to published experiments; you could also say that doing the experiments yourself would require resources &amp; time &amp; expertise that you don't have (assuming it's true, of course). If you can't convince the reviewer, you might still convince the editor, who can after all see the other two reviewers' comments.