I think the reason people call it worse is because, despite no change in quality, it feels worse. In my opinion, that's because the additional content, while technically impressive and even fun in the moment, doesn't feel like it's connected to the rest of the game content.
Engineering gives you more toys to play with, but when you're hunting for mats, it's all you do and it takes time away from everything else. If you do Power Play, it's its own reward and it's all you do. If you do multi-crew, it's all you do.
Of course, all earn you some credits, so it's not all completely disconnected... but it takes time from the other activities because they're not organically connected. The more semi-independent subsystems are added, the more thinly spread your game time becomes. And the game has great moments - the problem is that the additional content is not that rewarding and dilutes the great moments.
Just imagine if Power Play actually bought you rank progression with Fed/Empire/Alliance and improved your standing with select Engineers. Instead of ferrying PCAs around, you get Power-specific transport mission with different cargo to different places where chained missions then kick in. Maybe even multi-crew with NPCs as mission - flying as fighter pilot for an NPC convoy! None of these things mentioned are new, it's just chaining them together in a new way that makes missions, engineers, multi-crew, fighters, power play all lead into each other and hence encouraging (and rewarding) experimenting with all the mechanics.