I don't know what function the word "still" is intended to perform in this sentence. I, too, copy and paste using the context menu—sometimes, i.e.: when it is most appropriate and/or convenient to do so.

But the question is: what developers don't know about the standard keyboard shortcuts for copy and paste? Do they exist in any statistically significant numbers? ("There exists X" is not a very meaningful contribution if the Xs involved are something like 0.01% and are outnumbered by the number of programmers who write all their code on their mobile phone or whose version control strategy is to inscribe all their programs on a Tic Tac or a grain of rice or who think that Commodore 64-inspired homegrown operating systems are specially positioned to reveal the Word of God and offer protection against being pursued and persecuted by the CIA. Or are these some special breed of 9-to-5 darkmatter programmers who aren't going to show up on the radar, anyway?)