Not really. The only people who still need to support ie8 are in enterprise and the enterprise is usually a couple years behind. By the time they upgrade to bootstrap 4 ie8 support will have ended.
It's pretty bad. We once got a ticket to make sure our app works with "ALL BROWSERS" because it was broken in IE6. That ticket was 6 months ago. The users are out there.
Let's be clear – if you develop a service on the web, and a significant proportion of the users or target market uses IE8—enough that there's a positive ROI—then you are making a poor business decision by refusing to support it.
IE updates come in too slow, longer than once a year - it's been a year since IE 11, and IE 12 is not even on the near horizon. Chrome and Firefox have had how many updates since then? Even Safari has updated in that time. Windows 10 is slated for release after April 2015, that's a year and a half since their browser has been updated!
IE selectively implements standards for business reasons and IE has a history of versions sticking around for long periods of time.
IE's developer tools, even in IE 11 are horrible. They're not even a shade of what webkit, blink and mozilla based browsers offer.
Finally, and the most damning of reasons: you need to have a Windows machine or a slow and painful (and expensive) virtualization service to test IE if you don't use Windows to develop. We all use macs, if someone isn't using a mac they're more than likely using some linux distro. I haven't worked with a developer that used Windows as their main development machines in 5 years, and in that case they were actually developing a windows application.
IE doesn't deserve our attention, users can install a different browser or deal with it, but I haven't heard a user complain about it, at all. Once in a long while someone might ask, sheepishly, and not make a big fuss about it when we tell them that we don't really support IE.
I maintain such a web application myself. I work primarily on OS/X as my main development machine, and run various windows versions in virtual box in order to test these older browsers. Since the feature is usually completed using modern browsers up-front, there almost always a QA glitch that has to get worked out on IE8, chewing up another 20-30% of the total time of the project. Time that costs everyone in the business time, energy and pain. Think about that; 30% of the cost of development to support < 3% of the users.
When the large web companies like Google and Facebook remove support for these legacy browsers, every web developer on Earth cheers. Every instance of IE8 that is snuffed from existence is more time we can spend on creating great software features, and not wasting time back-porting.
We're enterprise and upgrading to 3.3 as we speak. We see a 4-8% of users coming in from older IE, mainly XP. We have customers in USA only.
Our public website: 3% IE7, 5.2% IE8
App: 1% IE7, 3.3% IE8
We are in an awkward spot of soon having to say, "Sorry ie8 wasn't a suitable upgrade".