The problem is that without User Agent sniffing in some circumstances there is no other way of working round a browser bug e.g. There are cases where browsers will report that it supports such feature using one of the feature checks but the implementation is garbage. The only way is to have a work around based on user-agent sniffing.
Sure a lot of developers abuse the feature but I fear this might create another set of problems.
Sure a lot of developers abuse the feature but I fear this might create another set of problems.