How does an interviewer measure good taste? You the interviewer could have been the result of a variety of metrics, none of which are good taste related. Bad taste is endemic in corporate and corporate startups(if you enter the millions in funding budget) for the simple reason that adequate taste is more reliable.
Edit: Within 30 seconds this got downvoted by cowards with no response. Enough with lurker culture. Say something.
1. For people who have worked on open source - just look through their code, their commit and you'll see how they think and operate.
2. If 1 isn't applicable, give them homework, not a test. Give them a very simple but very well documented task. Something along the lines of an authentication system, with password reset which is time restricted, basic encryption and security and that's it. This can be easily achieved in just about any language in several hundred lines of code. But given the adequate amount of time to think it through and develop it, you'll see if they come up with clever solutions to simple problems or a pile of duct tape hacks.
Edit: Within 30 seconds this got downvoted by cowards with no response. Enough with lurker culture. Say something.