Who cares about what developers wants you to do? Building/participation in pug raids will eventually get you a normal raid spot, while doing dailies/dungeons will not. If you really want to gear up, not just get 2 epic items per week and be OK with it, you will do pug raids.
As if you need more money than you get every month, but you refuse to get a second job because it is not intended to have two jobs
I mean, even participating in pug raids will give you a chance to get gear, and if you don't participate in pugs, you miss that chance. It is not forbidden, and if you have time to spend, do it and you will gear up (probably, since it is a wow, and drops are RNG based) faster