if my college/work forces me to use a certain (almost always proprietary) program and there's the option of using a web version instead of having to install the program on my local machine, I'm always going to pick the web version because that shit's (reasonably) samdboxed from my system. (using a college-provided system isn't an option right now because of corona, and I work in retail, so there's no room for negotiation there.)
without Javascript, that option is nonexistent for me. and not all my devices are powerful enough to run a Windows 10 VM to put the botnet in instead, whereas they /can/ run a web version. and when the class/job is done, I can just stop visiting that page instead of struggling to weed out whatever mess the program shat all over my system.
TL;DR Javascript is good, actually, because the alternative is far worse