As long as it’s done for practical purposes that actually help provide an interesting structure or aesthetic, rather than for the sake of “ZOMFG CUSTOM!!!”, I’m alright with it.
I’m of the mind that the simplest solution is often the best, and that something should only become complicated if totally necessary. For example, you don’t need to build a custom bone out of Technic just so you don’t have to use a basic CCBS bone, or build a totally custom torso when a basic torso frame has the exact same proportions and connection points that you want to achieve. However, you might want an armour piece to be positioned over the shoulder in a certain way that can’t be done using basic CCBS building, so in that scenario it wouldn’t be superfluous to use some Technic around the shoulder joint to position it in the way you want. You might also want to give your character a mechanism that the standard 2015 gearbox piece won’t accommodate, so again, building a custom Technic cradle for it is perfectly reasonable.
You really don’t have to make things “custom” for the sake of it. Too often have I seen MOCs with limbs or torsos jam-packed with Technic for what I can only assume is to give the impression of great technical prowess, that end up looking really blocky or messy. There’s nothing wrong with making things more technical, so long as there’s a point to doing so other than - again - “ZOMFG CUSTOM!!!”. Most of this year’s sets do demonstrate that quite nicely, only using Technic when they want to achieve something that basic CCBS building couldn’t - The positioning of Kopaka’s shoulder armour, for example, could not be achieved without Technic-based shoulders. The lower legs on the Beasts however demonstrate what superfluous custom building looks like - They’re built with Technic when they don’t really need to be, and suffer for it aesthetically.
Also, another point I’d like to make - How exactly does the user of Technic make these sets more like G1 sets? Very few - if any - G1 canister sets used Technic to the same extent that any of this year’s sets had. Only titan or vehicle builds from G1 are comparable, but seeing as what we’re getting in G2 are small set and canister set equivalents, that comparison doesn’t really work. Basically G2 sets are significantly more complex than their G1 ancestors.