Personally I do agree that it is good that FDev does react to very obvious exploits like that fertilizer buy-sell-glitch and remove ill-gotten gains despite the fact that it doesn't affect my gaming much, but I guess egg farming was less obviously an exploit. You actually have to do something in that, after all.
Not only do something, but it gets murkier because every single mechanic used in egg mining I've read here, elite reddit, or youtube videos shows those miners using nothing but the same mechanics that are seemingly ok elsewhere.
e.g. The egg is found via a static location mapped or plotted by directions learned - this is same as many other activities we used to have to locate the static spawn area of (although probes now make this much easier and not have to use the old planet coords flying skill)
The egg asteroid refreshes or respawns SSD resources on it when player moves sufficient distance away - this is same for other resources like planet SRV mat hunting. Drive away from a crater, go back and more meteorites.
The egg respawns on logout / login - same as for other data, mat, crashed anaconda, etc
Login/logout for egg respawn is made easier by moving just out of mass lock range, hence when logging back in, you keep your exact same position - making finding egg again lot easier - this has been true for preserving local area position since Horizon launched.
Everything is obviously an opinion, but I'm not sure how a fair person either doesn't call ALL of these things exploits, or none of them - because a player is just using the same tools available for all these activities. It is just egg mining has such a high payout potential that I suppose it catches flak