If you have a bad boss, find a new boss. You could just do the right thing, and if your boss has a problem with it, you're fired. Problem solved.
Of course, this assumes that it actually is your boss who's wrong, and you're not just ignorant of the market realities that your business operates in. If you want to avoid that JS hack and drop support for IE6, you better have numbers that show that it's a negligible part of your revenues. And if you do have those numbers, it will be much easier to convince your boss.
(True story: I was working on Google's visual redesign of 2010. As a team, we all estimated that supporting IE6 would double the development cost and add a minimum of 3 months to the schedule. We took this info - along with numbers for IE6 market share - to our managers, who took this to their managers, until it reached the executive level. The verdict: we didn't have to support IE6. This was the first version of Google Search that dropped support for it - Docs had dropped support a couple months earlier - and started the tidal wave of sites not supporting IE6.)
Of course, this assumes that it actually is your boss who's wrong, and you're not just ignorant of the market realities that your business operates in. If you want to avoid that JS hack and drop support for IE6, you better have numbers that show that it's a negligible part of your revenues. And if you do have those numbers, it will be much easier to convince your boss.
(True story: I was working on Google's visual redesign of 2010. As a team, we all estimated that supporting IE6 would double the development cost and add a minimum of 3 months to the schedule. We took this info - along with numbers for IE6 market share - to our managers, who took this to their managers, until it reached the executive level. The verdict: we didn't have to support IE6. This was the first version of Google Search that dropped support for it - Docs had dropped support a couple months earlier - and started the tidal wave of sites not supporting IE6.)