For many people who spend their time writing, the issue of descriptivism versus prescriptivism is a fascinating one. Are there rules of grammar and usage that people should follow? Sure. But are those rules defined by an elite group of language speakers and writers? Or should they simply be based on regularities of language usage by all speakers and writers? A fascinating question, with all types of issues.
For what it is worth, my view is basically that at any one time (within a group of language users), there are rules that define proper usage. But those rules change over time. At a certain point, the old conventions will give way to new ones, and those new ones will become the proper usages. So one day, perhaps pretty soon, the distinction between imply and infer is likely to evaporate and it will be proper to use them interchangeably.
Even if one is a descriptivist and agrees with that prediction, I think that one should be sad about the demise of the distinction. When the distinction is no longer recognized, it will be harder to convey precise information about whether the speaker is implying or the hearer is inferring. Perhaps in the new world new words will allow a speaker to convey the distinction, but there is no certainty and it seems like a lot of trouble to reinvent the wheel.
I recently came across another example where common usage appears to have diverged from proper usage, making our language less useful. The always interesting CGP Grey has an interesting video on family trees that raises a usage question (view the video at the 35 second point). What do you call the sister of your grandmother? Most people I speak to call her your great aunt. But Grey argues that it is actually your grand aunt. People on the generation level of your grandmother and grandfather should be called “grand,” including your aunt. By contrast, Grey argues your great aunt is the sister of your great grandmother – people on this generation level all have the name “great.” I think that this usage would be very helpful to people learning the names of people in their family trees. But departures from this usage have made it harder.